JP2000133174A - Image forming device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of inhibiting deterioration of element characteristics as the amount of electrons emitted from electron emission elements becomes stable, and restraining brightness from decreasing and becoming uneven. SOLUTION: To manufacture an image forming device in which an electron source substrate 1 with a plurality of electron emission elements aligned thereon and a faceplate 4 having a fluorescent film 7 are opposed together to form an envelope 5, a nonevaporative getter 9 that is thermally activated at a temperature of 250 deg.C or higher is formed within an image display area on the electron source substrate 1 and activated by heating during the process of evacuating the inside of the envelope 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a display device or an exposure device constituted by using an electron source having a plurality of electron-emitting devices, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a device for irradiating an electron beam emitted from an electron source to a phosphor as an image display member and causing the phosphor to emit light to display an image, a vacuum vessel containing the electron source and the image display member is included. The interior of the (envelope) must be kept at a high vacuum. The reason is that when gas is generated inside the vacuum vessel and the pressure rises, the degree of the effect depends on the type of gas, but it adversely affects the electron source, reduces the amount of electron emission, and makes it impossible to display a bright image. It is. Further, the generated gas is ionized by the electron beam to become ions, which are accelerated by an electric field for accelerating the electrons and collide with the electron source, which may damage the electron source. Further, in some cases, a discharge may be generated inside, and in this case, the device may be destroyed.

Normally, a vacuum container of an image display device is formed by combining glass members and bonding a bonding portion with frit glass or the like. Once the bonding is completed, the pressure is maintained in the vacuum container. Is done by the getter.

In recent years, a flat display using an electron source in which a large number of electron-emitting devices are arranged on a flat substrate has been developed. In order to secure a degree of vacuum, gas generated from an image display member is reduced to a getter. A characteristic problem is that it reaches the electron source before being diffused, causing a local pressure rise and accompanying deterioration of the electron source.

In order to solve this problem, there has been disclosed a structure in which a getter material is arranged in an image display area so that generated gas can be immediately adsorbed in a flat image display device having a specific structure. I have. Japanese Patent Application Laid-Open No. 9-82245 proposes a specific method of distributing a getter material over the entire image display area in order to suppress a pressure increase due to local gas release in the structure of the planar image display device. I have.

On the other hand, in the formation of a large-sized flat image display device, it is important that the structure has an easy manufacturing process, and a horizontal field emission type electron emission device is used as an electron emission device having such a structure. And a surface conduction electron-emitting device.

A horizontal field emission type electron-emitting device is formed by opposing a cathode (gate) having a sharp electron-emitting portion on a flat substrate, and is formed by a thin film deposition method such as vapor deposition, sputtering, and plating. It can be manufactured by ordinary photolithography technology.

The surface conduction type electron-emitting device emits electrons by passing a current through a conductive film partially having a high resistance portion.
One example is shown in Japanese Patent No. 5255.

[0009]

However, in the method of activating a getter as disclosed in Japanese Patent Application Laid-Open No. 9-82245, a dedicated heater wiring for activating the getter is laid or activated. In order to introduce a process for conversion, the structure and the process are complicated.

In the method of activating the getter by irradiating the electron beam, the energy obtained by the irradiation of the electron beam is converted into heat. Therefore, a huge amount of heat is required to generate the heat necessary for activating the getter. Power is required. Further, when this power is actually applied, a large load is applied to the electron source, and the electron-emitting device may be deteriorated. Also, components such as a substrate may be damaged by thermal distortion or the like.

An object of the present invention is to provide an image forming apparatus capable of solving the above-mentioned disadvantages, and more particularly, to provide an image forming apparatus in which the luminance does not change with time (decrease with time). It is another object of the present invention to provide an image forming apparatus in which variation in luminance over time in an image display area is small.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, an electron source substrate having a plurality of electron-emitting devices arranged thereon and a light emitting display substrate having an image forming member are arranged to face each other. In the method of manufacturing an image forming apparatus in which an envelope is formed, 25 mm is formed in an image display area on an electron source substrate.
A step of forming a non-evaporable getter which is activated by heating at a temperature of 0 ° C. or higher, wherein the non-evaporable getter is activated by heating in an exhaust step in the envelope. Things.

In the present invention, it is preferable that the activation of the non-evaporable getter, which is performed by heating in the exhaust step of the envelope, is performed at a temperature of 300 ° C. or more.

When a surface conduction electron-emitting device having a conductive film including an electron-emitting portion is applied as the electron-emitting device, a liquid containing a conductive film material is applied to the conductive film by an inkjet method. It is preferable to form it by the method described below.

The present invention includes an image forming apparatus manufactured by the above method.

According to the present invention, a non-evaporable getter (NE)
Since no special structure or process is required for the activation of G), an image forming apparatus having a long life by vacuum improvement can be easily provided at low cost. Further, when the NEG is activated, the gas discharged from each member of the image forming apparatus due to the heating is exhausted by an exhaust device such as a pump, so that the exhaust capability of the NEG is effectively used.

Further, since the formation of the conductive film constituting the electron-emitting device is performed by applying a liquid containing a conductive film material by an ink jet method, the patterning step in forming the electron-emitting device can be omitted. ,
Simplification of the process and suppression of contamination of the substrate can be achieved, and further, low cost and long life can be realized.

The application of a liquid containing a conductive film material by an ink-jet method is described in Japanese Patent Application Laid-Open No. 8-171850, etc., as a surface conduction electron-emitting device, an electron source substrate having the same, an image forming apparatus, and a method of manufacturing the same. As described, a metal-containing solution, which is the base material of the conductive film, is applied to the substrate in the form of droplets, and the conductive film for forming the electron-emitting portion is formed directly without the need for patterning. It is to be. Note that among the ink jet systems, a system in which droplets are ejected from a re-nozzle by deformation of a piezo element is particularly suitable for the present invention.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A basic configuration to which the present invention can be applied will be described.

FIG. 1 schematically shows a configuration example of the image forming apparatus of the present invention. Reference numeral 1 denotes an electron source in which a plurality of electron-emitting devices including a conductive film 108 including an electron-emitting portion and device electrodes 105 and 106 are arranged on a substrate, and are appropriately wired. 2 is a rear plate, 3 is a support frame,
4 is a face plate. The rear plate 2 to which the electron source 1 is fixed, the support frame 3 and the face plate 4 are adhered to each other using frit glass or the like to form an envelope 5.

The face plate 4 is formed by forming a fluorescent film 7 and a metal back 8 on a glass substrate 6, and includes a region where the fluorescent film 7 is formed (including the thickness of the vacuum space in the envelope 5). ) Is the image display area. The phosphor film 7 is made of only a phosphor in the case of a black-and-white image, but in the case of displaying a color image, pixels are formed by phosphors of three primary colors of red, green and blue, and a black conductive material is used between the pixels. Separate structure. The black conductive material is called a black stripe, a black matrix, or the like, depending on its shape. Details will be described later.

The metal back 8 is formed of a conductive thin film such as Al. The metal back 8 reflects light traveling toward the electron source 1 out of the light emitted from the phosphor toward the glass substrate 6 to improve the brightness, and the gas remaining in the envelope 5 reduces the electron emission. It also serves to prevent the phosphor from being damaged by the impact of ions generated by ionization by the wire. In addition, the image display area of the face plate 4 is provided with conductivity to prevent charge from being accumulated, and
Serves as an anode electrode.

Next, the fluorescent film 7 will be described. FIG.
(A) is a case where the phosphors 13 are arranged in a stripe shape, and the phosphors 1 of three primary colors of red (R), green (G), and blue (B).
3 are formed in order, and are separated by a black conductive material 12 therebetween. In this case, the portion of the black conductive material 12 is called a black stripe. FIG. 4B shows the fluorescent substance 13.
Are arranged in a grid pattern, and the dots are separated by the black conductive material 12. In this case, the black conductive material 1
2 is called a black matrix. There are several methods of arranging each color of the phosphor 13, and accordingly, the arrangement of the dots may employ a square lattice or the like in addition to the illustrated triangular lattice.

As a method for patterning the black conductive material 12 and the phosphor 13 on the glass substrate 6, a slurry method, a printing method, or the like can be used. After the fluorescent film 7 is formed,
The metal back 8 is formed.

FIG. 5 shows a configuration example of the electron source 1 to which the present invention can be applied. FIGS. 5A and 5B schematically show a configuration of an electron source 1 in which a plurality of two-dimensionally arranged electron-emitting devices are connected by matrix wiring. FIG. 5 (a)
5A is a plan view, and FIG. 5B shows a cross-sectional configuration along AA ′ in FIG. 5A. Although a surface conduction electron-emitting device is used for the electron source of the present embodiment, the present invention is not limited to this, and specifically, a field emission device, a MIM device, and the like generally referred to. Is also applicable.

Reference numeral 101 denotes an insulating substrate made of glass or the like;
Reference numeral 102 denotes an X-direction wiring (upper wiring), and reference numeral 103 denotes a Y-direction wiring (lower wiring). X direction wiring 102 and Y direction wiring 1
Reference numeral 03 is connected to the device electrodes 106 and 105 of each electron-emitting device.

A Y-directional wiring 103 is provided on a substrate 101, and an insulating layer 104 is further formed thereon. An X-directional wiring 102, device electrodes 105 and 106, and a conductive film 108 are formed thereon. Wiring 103 and element electrode 105
Are connected via a contact hole 107.

The various wirings and the like are formed by a combination of various thin film deposition methods such as a sputtering method, a vacuum evaporation method and a plating method, and a photolithography technique, or a printing method.

As a material for the opposing device electrodes 105 and 106, a general conductor material can be used. This includes, for example, Ni, Cr, Au, Mo, W, Pt, Ti, A
metals or alloys such as l, Cu, Pd and Pd, Ag, A
a printed conductor composed of a metal such as u, RuO ₂ , Pd—Ag or a metal oxide and glass, In ₂ O ₃ —SnO ₂
And the like and a semiconductor conductor material such as polysilicon.

As the conductive film 108, it is preferable to use a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage of the device electrodes 105 and 106, the resistance value between the device electrodes, forming conditions described later, and the like. The thickness is preferably in the range of several times 1 nm to several hundred nm, more preferably in the range of 1 nm to 50 nm. The resistance value is such that Rs is 10 ² to 10 ⁷ Ω /
The value of □. Note that Rs is an amount that appears when the resistance R of a thin film having a width w and a length 1 is set as R = Rs (l / w).

The material forming the conductive film 108 is Pd,
Pt, Ru, Ag, Au, Ti, In, Cu, Cr, F
metals such as e, Zn, Sn, Ta, W, Pd, PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ ,
HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , G
dB醐化matter such as _{4, TiC, ZrC, HfC,} TaC,
It is appropriately selected from carbides such as SiC and WC, nitrides such as TiN, ZrN and HfN, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles are formed). To form an island-like structure as a whole). The particle size of the fine particles is in the range of several times to several hundred nm of 0.1 nm, preferably in the range of 1 nm to 20 nm.

When the conductive film 108 is formed by an ink-jet method, any ink-jet device may be used as long as it can form an arbitrary droplet. Tens of ng
It is preferable to use an apparatus which can be controlled in the range of about 10 ng and can easily form a minute amount of droplets of about 10 ng or more. The material of the droplet may be in any state as long as the droplet can be formed, and examples thereof include a solution in which the above-described metal or the like is dispersed and dissolved in water, a solvent, or the like, an organic metal solution, or the like. .

Using the ink jet device as described above,
After a solution of the organometallic compound is applied as droplets only at predetermined positions and dried, the organometallic compound is thermally decomposed by heat treatment to form a conductive film 108 such as a metal or metal oxide. .

The electron-emitting portion 109 is formed by a high-resistance crack formed in a part of the conductive film 108, and depends on the thickness, film quality, and material of the conductive film 108, a method such as energization forming described later, and the like. It will be. Electron emission unit 109
In some cases, conductive fine particles having a particle size in the range of several times 0.1 nm to several tens of nm are present inside. The conductive fine particles are part of the elements of the material forming the conductive film 108,
Alternatively, it contains all elements. The electron emitting portion 109 and the conductive film 108 near the electron emitting portion 109 can also contain carbon and a carbon compound.

In the manufacturing method according to the present invention, the image display area on the electron source substrate having the above structure
Non-evaporable getter 9 activated at a temperature of 50 ° C. or higher
(See FIG. 1).

The position where the non-evaporable getter 9 is installed is, for example, on the X-direction wiring 102 as shown in FIG. Further, it is desirable that the installation areas are uniformly distributed over the entire image display area.

The non-evaporable getter 9 is made of Ti, Zr, Cr, Al, V, Nb, Ta, W, Mo,
One or more metals selected from Th, Ni, Fe, and Mn or alloys thereof are used.

The non-evaporable getter 9 is formed by a combination of various thin film deposition methods such as a sputtering method, a vacuum evaporation method and a plating method, and a photolithography technique.

The face plate 4, the support frame 3, and the rear plate 2 formed as described above are combined with the electron source 1 and other structures, and the support frame 3, the face plate 4, and the rear plate 2 are joined. I do. The bonding is performed by attaching frit glass to the bonding portion and heating the glass to 400 to 450 ° C. in a vacuum (referred to as a sealing step).

Thereafter, the inside of the envelope 5 is evacuated once,
Necessary processing such as activation processing of the electron source 1 is performed. Subsequently, a sufficient vacuum is secured inside the envelope 5 by exhausting and heating and degassing (baking), and the exhaust pipe (not shown) is heated and closed by a burner.

In the above-described baking process, the degassing process in the image forming apparatus is performed, and at the same time, the non-evaporable getter 9 is used.
Is heat activated. In the initial stage of baking, the degassing process is mainly performed, so that the exhaust capability of the non-evaporable getter 9 is not sufficiently secured. However, in the latter half of the baking, the gas emission is greatly reduced. Can be secured. In order to sufficiently perform degassing from each member constituting the image forming apparatus, heating at 200 ° C. or more is required, and more preferably 300 ° C.
° C or higher. The activation of the non-evaporable getter starts to be seen at 250 ° C. or higher. For this reason, the baking temperature is desirably 250 ° C. or higher. On the other hand, with regard to the baking time, gas release is large within several hours from the start of baking, and exhaustion characteristics of the non-evaporable getter can be sufficiently secured by heating at 250 ° C. or more in several tens to several hundred hours. As such, baking times are set between hours and hundreds of hours.

FIG. 2 shows an example of the time evolution of the emission rate of the main gases released during the heat treatment of the image forming apparatus in the present invention. The figure also shows a heating temperature profile, in which the temperature is increased and decreased at a rate of 1 ° C./min, respectively, and maintained at 300 ° C. for 10 hours. At the time of temperature rise, the gas release increases rapidly, and the gas release stops after 300 ° C. retention for about 3 hours. Note that 250
The same gas release characteristics are observed in the heating and holding at a temperature of ° C.

On the other hand, FIG. 3 shows a change in the exhaust capacity when the temperature and time for activating the non-evaporable getter are changed.
This shows that when the heating is performed at 300 ° C. or more, the exhaust capability of the non-evaporable getter can be sufficiently obtained in tens of minutes to tens of hours. Also, it can be seen that if heating is continued for several tens hours to several hundred hours even at 250 ° C., the same evacuation capacity as heating at 300 ° C. or more can be obtained.

As seen from the above example, if heating at 300 ° C. or more is performed for several hours or more while evacuating moderately,
The activation rate of the non-evaporable getter rises compared to the saturation of the released gas rate in the panel, so the exhaust capacity of the non-evaporable getter can surpass the released gas in several hours,
Even if the non-evaporable getter is activated by heating in the baking step of the image forming apparatus, the exhaust characteristics can be left after the temperature is lowered. Further, even at a somewhat lower temperature of 250 ° C., the exhaust characteristic of the non-evaporable getter can be obtained by performing the heating for several tens of hours or more. As a result, it is possible to provide an image forming apparatus having element characteristics with a long service life in a simple process.

Finally, a getter process is performed, which heats an evaporable getter 14 (in FIG. 1, a ring-shaped getter is schematically shown) provided in the envelope 5 to heat the inner wall of the envelope 5. This is a process of forming a film of a getter material by vapor deposition (referred to as "flash" of the getter). The getter film thus formed is located outside the image display area in the envelope 5.

As described above, according to the present invention, in a flat panel display in which a large number of electron-emitting devices are arranged on a substrate, a non-evaporable getter is arranged in an image forming area to maintain and maintain a higher vacuum in the panel. can do.

Next, NTS is performed by the above-described image forming apparatus.
An example of the configuration of a driving circuit for performing television display based on a C-system television signal will be described with reference to FIG. 6, reference numeral 81 denotes an image forming apparatus, 82 denotes a scanning circuit, 83 denotes a control circuit, 84 denotes a shift register, 85 denotes a line memory, 86 denotes a synchronizing signal separation circuit, 87 denotes a modulation signal generator, and Vx and Va denote DC voltages. Source.

The image forming apparatus 81 includes terminals _{Dox1 to Dox1
oxm} , terminals _{Doy1 to Doyn,} and a high voltage terminal Hv are connected to an external electric circuit.

Terminals D _{ox1 to} D _oxm are connected to an electron source provided in the image forming apparatus 81, that is, a group of surface-conduction electron-emitting devices arranged in a matrix of m rows and n columns in one row. A scanning signal for sequentially driving each (n elements) is applied.

[0051] The terminal D _Oy1 to _D oyn, modulation signal for controlling the output electron beam of each of the surface conduction electron-emitting devices of one row selected by a scan signal.

The high voltage terminal Hv is connected to a DC voltage source Va.
For example, a DC voltage of 10 kV is supplied, which is an accelerating voltage for applying sufficient energy to the electron beam emitted from the surface conduction electron-emitting device to excite the phosphor.

The scanning circuit 82 will be described. The circuit includes m switching elements (S _{1 to} S
_m is schematically shown). Each switching element selects either the output voltage of the DC voltage power supply Vx or 0 [V] (ground level),
To terminal D _ox1 of the image forming apparatus 81 is connected to D _oxm and electrically. Each of the switching elements S _{1 to} S _m operates based on the control signal T _scan output from the control circuit 83, and can be configured by combining switching elements such as FETs, for example.

In the case of the present embodiment, the DC voltage source Vx is based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting device, and the driving voltage applied to the unscanned device is an electron emission threshold. It is set to output a constant voltage that is equal to or lower than the value voltage.

The control circuit 83 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. The control circuit 83 in accordance with the synchronization signal T _sync sent from the synchronous signal separating circuit 86, T _scan, generating a respective control signal T _sft and T _mry to each unit.

The synchronizing signal separating circuit 86 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separating (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 86 is composed of a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a _Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is input to the shift register 84.

The shift register 84 converts the DATA signal input serially in time series into a serial / parallel format for each line of an image, and converts the DATA signal into a control signal _Tsft sent from the control circuit 83. (Ie, the control signal _Tsft may be rephrased as a shift clock of the shift register 84). The data for one line of the serial / parallel-converted image (corresponding to the driving data for n electron-emitting devices) are I _{d1 to} I _dn.
Are output from the shift register 84 as n parallel signals.

The line memory 85 stores data for one line of an image.
Is a storage device for storing data only for the required time,
Control signal T sent from control circuit 83_mry As appropriate
I_d1 Or I_dnIs stored. The stored content is I
_d'1 Or I_d'n And output to the modulation signal generator 87.
Is entered.

The modulation signal generator 87 outputs the image data I _d'1
To I _d'n , which is a signal source for appropriately driving and modulating each of the electron-emitting devices, and the output signal of which is _{supplied to} the surface conduction type in the image forming apparatus 81 through terminals _{Doy1 to Doyn.} Applied to the electron-emitting device.

The surface conduction electron-emitting device applicable to the present invention has the following basic characteristics with respect to the emission current _Ie . That is, electron emission has a clear threshold voltage _Vth , and electron emission occurs only when a voltage equal to or higher than _Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device. Therefore, when a pulse-like voltage is applied to the device, for example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied. Outputs an electron beam. At that time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Further, by changing the pulse width Pw, it is possible to control the total amount of charges of the output electron beam.

Therefore, as a method of modulating the electron-emitting device according to the input signal, a voltage modulation method, a pulse width modulation method, or the like can be adopted. When implementing the voltage modulation method, the modulation signal generator 87 generates a voltage pulse of a fixed length, and a voltage modulation circuit capable of appropriately modulating the peak value of the voltage pulse according to input data. Can be used.

When implementing the pulse width modulation method,
As the modulation signal generator 87, a pulse width modulation circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 84 and the line memory 85
Can be adopted as a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separating circuit 86 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronizing signal separating circuit 86. Just do it. In connection with this, the circuit used for the modulation signal generator 87 differs slightly depending on whether the output signal of the line memory 85 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, for example, the D /
An A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 87 includes, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 87 can employ, for example, an amplifier circuit using an operational amplifier or the like, and can add a level shift circuit or the like as necessary. In the case of the pulse width modulation method, for example, a voltage-controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device can be added as necessary.

In the image forming apparatus according to the present invention which can take such a configuration, each of the electron-emitting devices is provided with a terminal D outside the container.
_ox1 to D _oxm, by applying a voltage via the D _Oy1 to _D oyn, electron emission occurs. A high voltage is applied to the metal back 8 or the transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons are
The light collides with the fluorescent film 7 and emits light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. The input signal has been described in the NTSC system. However, the input signal is not limited to this. In addition to the PAL and SECAM systems,
A TV signal composed of more scanning lines than these (for example,
A high-definition TV system such as the MUSE system can also be adopted.

The image forming apparatus of the present invention can be used not only as a display device for a television broadcast, a display device such as a video conference system or a computer, but also as an image forming device as an optical printer using a photosensitive drum or the like. Can be used.

[0069]

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and each element within a range in which the object of the present invention is achieved. This also includes those in which substitutions or design changes have been made.

[Embodiment 1] The image forming apparatus of this embodiment is
It has a configuration similar to that of the device schematically shown in FIG. 1, and the non-evaporable getter film is arranged on almost the entire surface of the X-direction wiring (upper wiring) 102 in the image display area.

The image forming apparatus of this embodiment has an electron source 1 in which a plurality of (100 rows × 300 columns) surface conduction electron-emitting devices are arranged in a simple matrix on a substrate.

FIG. 7 shows a partial plan view of the electron source 1. FIG. 8 is a sectional view taken along the line BB 'in FIG. However, in FIGS. 7 and 8, the same reference numerals denote the same components. Here, 101 is an electron source substrate made of a glass substrate, 102 is an X-direction wiring (also called an upper wiring), 103 is a Y-direction wiring (also called a lower wiring), 104 is an interlayer insulating layer, and 105 and 1
06 is the device electrode, 107 is the device electrode 105 and the lower wiring 10.
A contact hole 108 for electrical connection with the third electrode 3 is a conductive film including an electron emitting portion 109.

Hereinafter, a method of manufacturing the image forming apparatus according to the present embodiment will be described with reference to FIG.

Step-a The glass substrate was sufficiently washed with a detergent, pure water and an organic solvent. A 0.5 μm thick silicon oxide film was formed thereon by a sputtering method to form an electron source substrate 101. A photoresist (AZl370 / Hoechst) was spin-coated and baked thereon, and then a photomask image was exposed and developed to form a resist pattern of the lower wiring 103. Furthermore, 5 nm thick Cr,
After sequentially depositing Au having a thickness of 600 nm, unnecessary portions of the Au / Cr deposited film were removed by lift-off, and a lower wiring 103 having a desired shape was formed (FIG. 9A).

Step-b Next, an interlayer insulating film 104 made of a silicon oxide film having a thickness of 1.0 μm was deposited by RF sputtering (FIG. 9).
(B)).

Step-c A photoresist pattern for forming the contact hole 107 is formed in the silicon oxide film deposited in the step-b, and the interlayer insulating layer 104 is etched using the photoresist pattern as a mask to form the contact hole 107. Etching is performed by RIE (Reactive) using CF ₄ and H ₂ gas.
Ion Etching) method (FIG. 9 (c)).

Step-d A pattern was formed such that a resist was applied to portions other than the contact hole 107, and 5 nm thick Ti and 500 nm thick Au were sequentially deposited by vacuum evaporation. Unnecessary portions were removed by lift-off to bury the contact holes 107 (FIG. 9D).

Step-e After that, a pattern to become the device electrodes 105 and 106 is formed by a photoresist (RD-2000N-41 / manufactured by Hitachi Chemical Co., Ltd.), and a 5 nm-thick Ti,
Ni having a thickness of 100 nm was sequentially deposited. The photoresist pattern was dissolved with an organic solvent, the Ni / Ti deposited film was lifted off, and the device electrode interval G was 3 μm and the device electrode width was 30.
9 μm device electrodes 105 and 106 were formed (FIG. 9).
(E)).

Step-f After a photoresist pattern of the upper wiring 102 is formed on the device electrodes 105 and 106, Ti having a thickness of 5 nm and a thickness of 5
Au having a thickness of 00 nm was sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form an upper wiring 102 having a desired shape (FIG. 9F).

Step-g A Cr film (not shown) having a film thickness of 100 nm is deposited and patterned by vacuum evaporation, and a Pd amine complex solution (ccp4230 / Okuno Pharmaceutical Co., Ltd.) is spin-coated thereon with a spinner. A heating and baking treatment was performed at 10 ° C. for 10 minutes. The thus-formed conductive film 108 for forming an electron-emitting portion composed of fine particles made of Pd as the main element had a thickness of 8.5 nm and a sheet resistance of 3.9 × 10 ⁴ Ω / □ (FIG. 9 (g)). Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state in which the fine particles are individually dispersed and arranged, but also in a state in which the fine particles are adjacent to each other or overlapped (island shape). Inclusive).

Step-h The Cr film and the conductive film 1 for forming the electron-emitting portion after firing.
08 was re-etched with an acid etchant to form a desired pattern (FIG. 9 (h)).

Through the above steps, a plurality (100 rows × 300 columns) of conductive films 108 for forming electron-emitting portions were connected to the electron source substrate 101 in a simple matrix composed of the upper wiring 102 and the lower wiring 103. It was taken.

Step-i A metal mask having an opening corresponding to the X-direction wiring (upper wiring) 102 is put on the electron source substrate 101, aligned and fixed, and set in a sputtering apparatus. Zr-V-Fe = 70 wt%: 25 wt%:
An alloy layer having a thickness of 300 nm was formed by a sputtering method using an alloy of 5 wt% to obtain a non-evaporable getter film 9 (FIG. 9 (i)).

As described above, the electron source 1 having the non-evaporable getter was formed.

Step-j Next, the face plate 4 shown in FIG. 1 was prepared as follows.

The glass substrate 6 was sufficiently washed with a detergent, pure water and an organic solvent. On top of this, 0.1 μm of ITO was deposited by a sputtering method to form a transparent electrode (not shown). Subsequently, a phosphor film 7 was applied by a printing method, and the surface was smoothed (generally called “filming”) to form a phosphor portion. The fluorescent film 7 was a fluorescent film shown in FIG. 4A in which stripe-shaped phosphors (R, G, B) 13 and black conductive materials (black stripes) 12 were alternately arranged. Further, a metal back 8 made of an Al thin film was formed on the fluorescent film 7 to a thickness of 0.1 μm by a sputtering method.

Step-k Next, the envelope 5 shown in FIG. 1 was prepared as follows.

After fixing the electron source 1 formed by the above-described process to the rear plate 2, the support frame 3 and the face plate 4 are combined, and the lower wiring 103 and the upper wiring 102 of the electron source 1 are connected to the row selection terminals 10. And the signal input terminal 11, respectively, and the positions of the electron source 1 and the face plate 4 were adjusted and sealed to form the envelope 5. The method of sealing is to apply frit glass to the joint and apply it in a vacuum chamber.
Heat treatment was performed at 50 ° C. for 30 minutes to perform bonding. The fixing of the electron source 1 and the rear plate 2 was performed in the same manner.
When the rear plate and the face plate were arranged, a ring getter (evaporation type getter) 14 of Ba was arranged at a predetermined position at the same time.

Before describing the next step, the vacuum apparatus used in the subsequent steps will be described with reference to FIG.

The image forming apparatus 121 is connected to a vacuum container 123 via an exhaust pipe 122. The vacuum container 123 is connected to an exhaust device 125, and a gate valve 124 is provided therebetween. In the vacuum container 123,
Pressure gauge 126, quadrupole mass analyzer (Q-mass) 12
7 is attached so that the internal pressure and each partial pressure of the residual gas can be monitored. Since it is difficult to directly measure the pressure and the partial pressure in the envelope 5, the pressure and the partial pressure of the vacuum vessel 123 are measured, and these values are regarded as those in the envelope 5. The exhaust device 125 is an ultra-high vacuum exhaust device including a sorption pump and an ion pump. A plurality of gas introduction devices are connected to the vacuum container 123,
The substance stored in the substance source 129 can be introduced. The introduced substance is filled in a cylinder or an ampoule according to the type, and the introduced amount can be controlled by the gas introduction amount control device 128. The gas introduction amount control means 128
Depending on the type of introduced substance, flow rate, required control accuracy, etc.,
Needle valves, mass flow controllers and the like are used. In this embodiment, benzonitrile contained in a glass ampoule was used as the substance source 129, and the gas introduction amount control means 128 was a slow leak valve.

The following steps were performed using the above vacuum processing apparatus.

Step-1 The inside of the envelope 5 is evacuated, the pressure is reduced to 1 × 10 ⁻³ Pa or less, and the conductive films 108 for forming a plurality of electron emission portions arranged on the electron source substrate 101 are formed. The following processing (called forming) for forming an electron-emitting portion was performed.

As shown in FIG. 11, the Y-directional wiring 103 is connected in common and connected to the ground. A control device 131 controls the pulse generator 132 and the line selection device 134. 133 is an ammeter. The line selection device 134 selects one line from the X-direction wiring 102 and applies a pulse voltage to it. The forming process was performed for each element row in the X direction (300 elements). The waveform of the applied pulse was a triangular wave pulse as shown in FIG. 12A, and the peak value was gradually increased. Pulse width T ₁ = 1ms
ec. , Pulse interval T ₂ = 10 msec. And Further, a rectangular wave pulse having a peak value of 0.1 V was inserted between the triangular wave pulses, and the current was measured to measure the resistance value of each row. When the resistance value exceeded 3.3 kΩ (1 MΩ per element), the forming of the row was terminated, and the process of the next row was started. This was performed for all the rows, and the forming of all the conductive films (the conductive films 108 for forming the electron emission portions) was completed, and the electron emission portions 109 were formed in each of the conductive films 108 (FIG. 9 (l)). )).

Step-m Benzonitrile is introduced into the vacuum vessel 123 of FIG. 10, the pressure is adjusted to 1.3 × 10 ⁻³ Pa, and each electron-emitting device is measured while measuring the device current _If. A pulse was applied to the conductive film 108 constituting, and an activation process of each electron-emitting device was performed. Pulse generator 132 (see FIG. 11)
Is a rectangular waveform shown in FIG. 12 (b), the peak value is 14V, and the pulse width T ₁ = 100 μsec.
c. The pulse interval is 167 μsec. It is. 167 μsec. The selection line is sequentially switched from D _x1 to D _x100 every time, and as a result, T ₁ = 100 μsec. , T ₂ = 16.7 mse
c. Is applied with a slightly shifted phase for each row.

The ammeter 133 is used in a mode for detecting the average of the current value in the ON state of the rectangular pulse (when the voltage is 14 V), and this value becomes 600 mA (2 mA per element). At this point, the activation process ends,
The inside of the envelope 5 was evacuated.

Step-n The entire image forming apparatus 121 and the vacuum vessel 123 are kept at 300 ° C. by a heating device (not shown) while continuing the evacuation.
Hold for 0 hours. By this treatment, benzonitrile and its decomposed products, which are considered to have been adsorbed on the envelope 5 and the inner wall of the vacuum vessel 123, were removed. This is Q-ma
It was confirmed by observation with ss127. In this step, the heating / exhaust holding of the image forming apparatus not only removes the gas from the inside, but also performs the activation of the non-evaporable getter 9.

Step-o After confirming that the pressure was 1.3 × 10 ⁻⁵ Pa or less, the exhaust pipe was heated and closed with a burner. continue,
The evaporable getter 14 previously set outside the image display area is reflashed by high-frequency heating.

As described above, the image forming apparatus of this embodiment was prepared.

[Embodiment 2] In the present embodiment, the process -n
Example 1 except that the following step -n 'was performed instead of
An image forming apparatus was prepared in the same manner as described above.

Step-n ′ While the evacuation is continued, the entire image forming apparatus 121 and vacuum vessel 123 are heated to 250 ° C. by a heating device (not shown).
Held for 00 hours. By this treatment, benzonitrile and its decomposed products, which are considered to have been adsorbed on the envelope 5 and the inner wall of the vacuum vessel 123, were removed. This is Qm
It was confirmed by observation with ass127. In this step, the heating / exhaust holding of the image forming apparatus not only removes the gas from the inside, but also performs the non-evaporable getter 9.
Is also performed.

[Embodiment 3] In this embodiment, the above-mentioned step-g
An image forming apparatus was prepared in the same manner as in Example 1, except that the following step -g 'was performed instead of step -h. FIG. 13 schematically shows a plan view of the electron source created in this embodiment.

Step-g 'Subsequently, a solution of an ethanolamine complex of organic palladium is applied as droplets using a bubble jet type ink jet apparatus to form a film to be a precursor of the conductive film 108. At this time, the interval between the X-direction wirings 102 is about 350
μm, the interval between the Y-direction wirings 103 is about 270 μm, and the precursor film has a substantially circular shape and a diameter of about 40 μm. Subsequently, a heat treatment was performed at 300 ° C. for 10 minutes to change the precursor film into a conductive film 108 made of PdO fine particles. Since the conductive film in this embodiment is directly drawn, no patterning step is required.

[Comparative Example] In this comparative example, an image forming apparatus similar to that of the first embodiment was manufactured by the following steps. In addition,
FIG. 14 schematically shows a plan view of the electron source created in this comparative example.

Steps -a to e Same as in Example 1.

Step-f After a photoresist pattern of the upper wiring 102 and the non-evaporable getter activating wiring 110 is formed on the device electrodes 105 and 106, Ti having a thickness of 5 nm and A having a thickness of 500 nm are formed.
u were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form an upper wiring 102 and a getter activation wiring 110 having desired shapes (see FIG. 14).

Steps-g to m Same as in Example 1.

Step-n The entire image forming apparatus 121 and the vacuum vessel 123 are kept at 150 ° C. by a heating device (not shown) while continuing the evacuation.
Hold for hours.

Step-n 'The non-evaporable getter 9 is activated. A pulse similar to that used in the activation process of the electron source (described in step-m) is applied to cause the electron-emitting device to emit an electron beam. -1 kV is applied to the high voltage terminal Hv, and -5 kV is applied to the getter activation wiring 110.
0 V was applied. As a result, the electrons emitted from each electron-emitting device are attracted to and collide with the non-evaporable getter layer 9 arranged on the X-directional wiring 102, thereby giving energy. Thereby, the non-evaporable getter 9 is activated.

Step-o Common to Example 1.

Thus, an image forming apparatus as a comparative example was prepared.

In the image forming apparatuses of Examples 1 to 3 according to the present invention, the decrease in luminance was suppressed lower than that of the image forming apparatus of the comparative example. As a result, the image forming apparatus according to the present invention can form an image with higher luminance and excellent operation stability.

[0112]

As described above, according to the present invention, an image in which an envelope is formed by arranging an electron source substrate on which a plurality of electron-emitting devices are arranged and a light emitting display substrate having an image forming member are opposed to each other. In manufacturing the forming apparatus, a non-evaporable getter that is heated and activated at a temperature of 250 ° C. or higher is formed in an image display area on an electron source substrate, and the non-evaporable getter is exhausted in an envelope. By activating by heating in the process, there is no need for a special structure or process for activating the non-evaporable getter, so an image forming apparatus that has a longer life by vacuum improvement can be easily provided at low cost. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention.

FIG. 2 is a diagram illustrating a change over time in a release rate of a gas released during baking of an image forming apparatus.

FIG. 3 is a diagram showing how the exhaust characteristics of a non-evaporable getter used in the present invention change depending on the heating temperature and time for activation.

FIG. 4 is a diagram showing an arrangement pattern of a phosphor and a black conductive material used in the present invention.

FIG. 5 is a schematic diagram showing an example of an electron source to which the present invention is applied, in which surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 6 is a block diagram illustrating an example of a driving circuit for performing display in accordance with an NTSC television signal in the image forming apparatus of the present invention.

FIG. 7 is a plan view schematically illustrating an example of an electron source arranged in a simple matrix and formed by applying the present invention.

FIG. 8 is a cross-sectional view schematically showing an example of an electron source arranged in a simple matrix and formed by applying the present invention.

FIG. 9 is a view showing a process of forming an electron source in which the present invention is applied and a surface conduction electron-emitting device is arranged in a simple matrix.

FIG. 10 is a schematic view of a vacuum evacuation apparatus for performing a forming and activation step in the manufacturing process of the image forming apparatus of the present invention.

FIG. 11 is a schematic view showing a connection method for forming and activating steps in the manufacturing process of the image forming apparatus of the present invention.

FIG. 12 is a schematic diagram showing voltage waveforms used in forming and activating steps in the manufacturing process of the image forming apparatus of the present invention.

FIG. 13 is a plan view schematically showing the electron sources arranged in a simple matrix and created in Example 3.

FIG. 14 is a plan view schematically showing electron sources arranged in a simple matrix and created in a comparative example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electron source 2 rear plate 3 support frame 4 face plate 5 envelope 6 glass substrate 7 fluorescent film 8 metal back 9 non-evaporable getter 10 row selection terminal 11 signal input terminal 12 black conductive material 13 phosphor pattern 14 evaporation type Getter 81 Image forming apparatus 82 Scanning circuit 83 Control circuit 84 Shift register 85 Line memory 86 Synchronous signal separation circuit 87 Modulation signal generator Vx, Va DC voltage source 101 Electron source substrate 102 Upper wiring (X direction wiring) 103 Lower wiring (Y Direction wiring) 104 interlayer insulating layer 105, 106 device electrode 107 contact hole 108 conductive film 109 electron emission section 110 getter activation wiring 121 image forming apparatus 122 exhaust pipe 123 vacuum vessel 124 gate valve 125 exhaust apparatus 126 pressure gauge 127 Q -Mass 128 g Introducing amount control means 129 material source 131 controller 132 pulse generator 133 ammeter 134 line selection device

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yasuhiro Hamamoto 3- 30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Kazuya Shigeoka 3- 30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Yoshitaka Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Inc. (reference) 5C012 AA01 5C032 JJ08 JJ11 5C036 EE01 EF01 EF06 EF09 EG12 EG50 EH26

Claims (4)

[Claims] 1. A method for manufacturing an image forming apparatus, comprising: an electron source substrate on which a plurality of electron-emitting devices are arranged; and a light emitting display substrate having an image forming member, which are arranged to face each other to form an envelope. Forming a non-evaporable getter in which heat activation is performed at a temperature of 250 ° C. or more in an image display area on the substrate, wherein the non-evaporable getter is used in an evacuation step in the envelope. A method for manufacturing an image forming apparatus, wherein the method is activated by heating. 2. The method according to claim 1, wherein the activation of the non-evaporable getter performed by heating in the exhaust process in the envelope is performed by 300
2. The method according to claim 1, wherein the method is performed at a temperature equal to or higher than C. 3. An electron-emitting device having a conductive film including an electron-emitting portion, wherein the step of forming the conductive film includes applying a liquid containing the conductive film material by an inkjet method. 3. The method according to claim 1, further comprising the step of: 4. An image forming apparatus manufactured by the method according to claim 1.