JP2000243326A - Image forming device and inspection method of degree of vacuum inside of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily inspect a degree of vacuum in an image forming device even after a making process of the image forming device and sealing of an exhaust pipe. SOLUTION: In an image forming device having an electron source having plural electron emitting elements 54 on a base board in an envelope, an image forming member oppositely arranged on the base board and a getter material (a nonevaporation type getter 57) for maintaining a degree of vacuum inside of the envelope, a vacuum degree detecting means is arranged to detect a degree of vacuum inside of the image forming device on the basis of a change in a resistance value of the getter material (the nonevaporation type getter 57).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with an electron source and an image forming member (phosphor) for forming an image by irradiating an electron beam emitted from the electron source in a vacuum vessel. The present invention relates to an image forming apparatus provided with means for inspecting the degree of vacuum inside a vacuum container, and a method for inspecting the degree of vacuum.

[0002]

2. Description of the Related Art CRTs have been widely used as image forming apparatuses for displaying images using electron beams.

On the other hand, in recent years, flat-panel display devices using liquid crystal have become widespread in place of CRTs. However, since the flat panel display device is not a self-luminous type, there is a problem that a backlight must be provided, and development of a self-luminous type display device has been desired. As a self-luminous display device, a plasma display has recently begun to be commercialized, but the principle of light emission is different from that of a conventional CRT, and it can be said that it is slightly inferior to a CRT due to the contrast of images and good color development. It is the present situation that does not get. Further, if a plurality of electron-emitting devices are arranged and used in a flat panel image forming apparatus, it is expected that light emission of the same quality as that of a CRT can be obtained, and much research and development has been carried out. The electron-emitting device constituting the electron source of the flat plate type image forming apparatus is required to be able to form uniformly over a large area, and it is desired that the manufacturing process be simple.

As a typical example of an electron-emitting device that may satisfy this condition, a surface conduction electron-emitting device having a structure schematically shown in FIG. 13 and an image forming apparatus using the same have been proposed.

FIGS. 13A and 13B show a surface conduction electron-emitting device and an image forming apparatus using the same, wherein FIG. 13A is a plan view and FIG. 13B is a sectional view. In FIG. 13, 1
31 denotes a substrate, 132 and 133 denote device electrodes, 134 denotes a conductive thin film, and 135 denotes an electron-emitting portion.

The details of the structure and manufacturing method of the electron-emitting device and the image forming apparatus are described in, for example,
It is described in JP-A-235255, JP-A-7-235275, and the like. Hereinafter, a brief description will be given of a method of manufacturing an image forming apparatus in which a plurality of such surface conduction electron-emitting devices are arranged on a substrate.

For the arrangement of elements on a substrate, for example,
A large number of electron-emitting devices are arranged in parallel, a large number of rows of electron-emitting devices having both ends of each element connected by wiring (called a row direction), and arranged in a direction orthogonal to the wiring (column direction). ), An array configuration (called a ladder type) in which electrons are controlled and driven by a control electrode (called a grid) installed in a space above the electron source, and n
An arrangement form (referred to as a simple matrix arrangement) in which the Y-directional wirings are disposed via an interlayer insulating layer, and the X-directional wiring and the Y-directional wiring are connected to a pair of device electrodes of the surface conduction electron-emitting device, respectively. No.

Next, the simple matrix arrangement will be described in detail.

According to the three basic features of the surface conduction electron-emitting device described in the above publication, the electrons emitted from the surface conduction electron-emitting device are located between the opposing device electrodes when the threshold voltage or more is exceeded. Can be controlled by the peak value and width of the pulse-like voltage applied to the. On the other hand, below the threshold voltage, almost no electrons are emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, if the pulse-like voltage is appropriately applied to each of the devices, the surface-conduction electron-emitting device is selected according to an input signal, and the electron is selected. The amount of release can be controlled.

Hereinafter, the configuration of the electron source substrate constructed based on this principle will be described with reference to FIG.

As shown in FIG. 11, m X-direction wirings 5
2 is composed of D _x1 , D _x2 ,..., D _xm , and is formed on the insulating substrate 51 by a vacuum evaporation method, a printing method, a sputtering method, or the like, and is made of a conductive metal or the like having a desired pattern. The material, the film thickness, the wiring width, and the like are designed so that a substantially uniform voltage is supplied to many surface conduction electron-emitting devices. An interlayer insulating layer (not shown) is provided between the m X-directional wirings 52 and the n Y-directional wirings 53 and is electrically separated to form a matrix wiring (where m and n are: Both are positive integers).

The interlayer insulating layer (not shown) is made of, for example, SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like, and has a desired shape on the entire surface or a part of the substrate 51 on which the X-direction wiring 52 is formed. The thickness, material, and manufacturing method are appropriately set so as to be formed, and particularly to withstand the potential difference at the intersection of the X-direction wiring 52 and the Y-direction wiring 53. The X-direction wiring 52 and the Y-direction wiring 53 are led out as external terminals.

Further, opposing electrodes (not shown) of the surface conduction electron-emitting device 54 are provided with m X-direction wirings 52 (D _x1 , D
_x2, ···, D _xm) and n Y-directional wirings 53 (D _y1, D
_y2 ,..., _Dyn ) are electrically connected to each other by a connection made of a conductive metal or the like.

Here, m X-directional wires 52 and n Y wires
Some or all of the constituent elements of the conductive metal of the element electrode facing the directional wiring 53 and the connection 56 may be the same or different.

As will be described later in detail, the X-direction wiring 52 is provided with a scanning signal (not shown) for scanning a row of the surface conduction electron-emitting devices 54 arranged in the X direction in accordance with an input signal. It is electrically connected to the scanning signal applying means. On the other hand, the Y-direction wiring 53 is a modulation signal generating means (not shown) for applying a modulation signal for modulating each column of the surface conduction electron-emitting devices 54 arranged in the Y direction according to an input signal.
Is electrically connected to

Further, the drive voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

Next, an electron source using the electron source substrate manufactured as described above, and an image forming apparatus used for display and the like will be described with reference to FIGS. FIG. 7 is a schematic diagram of a fluorescent film, and FIG. 12 is a basic configuration diagram of an image forming apparatus.

In FIG. 12, reference numeral 14 denotes an electron-emitting device 13.
, A rear plate 15 to which the electron source substrate 14 is fixed, 4 a fluorescent film 7 on the inner surface of the glass substrate 6
And a face plate on which a metal back 8 and the like are formed. Reference numeral 3 denotes a support frame, which is coated with frit glass on the rear plate 15, the support frame 3, and the face plate 4 and is heated at 400 to 500 ° C. in the air or in nitrogen.
By baking for 0 minutes or more, sealing is performed to form the envelope 5.

In FIG. 12, reference numerals 11 'and 12' denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of a surface conduction electron-emitting device. Also, the wiring to these device electrodes, if the device electrode and the wiring material are the same,
It may be called an element electrode. The envelope 5 is, as described above,
Although the face plate 4, the support frame 3, and the rear plate 15 are provided, the rear plate 15 is provided mainly for the purpose of reinforcing the strength of the substrate 14. The body rear plate 15 is unnecessary, and the support frame 3 may be directly sealed to the substrate 14, and the envelope 5 may be configured by the face plate 4, the support frame 3, and the substrate 14.

On the other hand, by installing a support (not shown) called a spacer between the face plate 4 and the rear plate 15, the envelope 5 having sufficient strength against atmospheric pressure can be formed. .

At the time of performing the above-mentioned sealing, in the case of a color image forming apparatus, it is necessary to make the respective phosphors shown in FIG. 7 correspond to the electron-emitting devices. There is.

The envelope 5 passes through an exhaust pipe (not shown).
After the degree of vacuum is set to about 3 × 10 ⁻⁵ Pa, sealing is performed.

In some cases, getter processing is performed to maintain the degree of vacuum after the envelope 5 is sealed. This is because the getter material disposed at a predetermined position (not shown) in the envelope 5 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 5 is sealed. This is a process for forming a deposited film. The getter material is usually composed mainly of Ba or the like.
The degree of vacuum is maintained at 3 × 10 ⁻³ or 1.3 × 10 ⁻⁷ Pa.

In the image display device completed as described above, each of the electron-emitting devices has external terminals D _{x1 to} D _xm and D _y1.
To _Dyn to emit electrons by applying a voltage, apply a high voltage of several kV or more to the metal back 8 or a transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam, and The image is displayed by causing excitation and light emission by colliding with the light.

[0025]

By the way, in the process of producing an image forming apparatus using the above-mentioned surface conduction electron-emitting device, it is essential to develop a production process so that defective products are not generated as much as possible. That is, if a defective product occurs in the production process, the cost of the constituent members is wasted accordingly, and it becomes difficult to provide the product at low cost. For that purpose, it is necessary to detect a defective portion at an early stage and to correct the defective portion each time.

If the degree of vacuum inside the image forming apparatus becomes abnormal (vacuum leak or the like), unnecessary gas components are mixed into the image forming apparatus. The mixed gas is ionized by the electrons emitted from the electron source, accelerated by an electric field formed between the electron source and the image display member, and damages the electron source or causes a discharge to cause the electron source to be discharged. It may be destroyed. In such a case, the image forming apparatus becomes defective.

Therefore, it has been desired to develop a process of manufacturing the image forming apparatus and a step of easily checking the degree of vacuum in the image forming apparatus even after sealing the exhaust pipe.

[0028]

In order to achieve the above object, an image forming apparatus according to the present invention comprises: an electron source having a plurality of electron-emitting devices disposed on a substrate in an envelope; In an image forming apparatus having an image forming member disposed to face a substrate and a getter material for maintaining a degree of vacuum inside the envelope, the image forming apparatus is configured to perform the image forming apparatus based on a change in a resistance value of the getter material. It is characterized in that a vacuum degree detecting means for detecting the degree of vacuum inside is provided.

Further, the image forming apparatus according to the present invention is characterized in that, in an envelope, an electron source having a plurality of electron-emitting devices disposed on a substrate, and an image forming member disposed to face the substrate. ,
In an image forming apparatus having a getter material for maintaining the degree of vacuum inside the envelope, the degree of vacuum inside the image forming apparatus is changed based on a change in the resistance value of a non-evaporable getter material formed by a thermal spraying method. It is characterized in that a vacuum degree detecting means for detecting is provided.

Further, according to the method for inspecting the degree of vacuum inside an image forming apparatus according to the present invention, an electron source having a plurality of electron-emitting devices provided on a substrate in an envelope is provided. A method for inspecting the degree of vacuum inside an image forming apparatus having an arranged image forming member and a getter material for maintaining a degree of vacuum inside the envelope, based on a change in resistance value of the getter material. And detecting a degree of vacuum inside the image forming apparatus.

According to the method of inspecting the degree of vacuum inside an image forming apparatus according to the present invention, an electron source in which a plurality of electron-emitting devices are disposed on a substrate in an envelope is provided. In a method for inspecting the degree of vacuum inside an image forming apparatus having a placed image forming member and a getter material for maintaining the degree of vacuum inside the envelope, a non-evaporable type formed by a thermal spraying method is provided. It is characterized in that the degree of vacuum inside the image forming apparatus is detected based on a change in the resistance value of the getter material.

Here, it is preferable that the non-evaporable getter material contains metal Zr as a constituent element.

The thickness of the non-evaporable getter material formed by the thermal spraying method is preferably 10 to 100 μm.

Further, the electron source may be an electron source in which a plurality of electron-emitting devices arranged in a matrix are arranged on a substrate.

Further, the electron source may have a surface conduction electron-emitting device.

[0036]

Embodiments of the present invention will be described below.

FIG. 1 schematically shows an example of the configuration of an image forming apparatus with a resistance measuring terminal according to the present invention. In FIG. 1, reference numeral 1 denotes an electron source in which a plurality of electron-emitting devices 13 are arranged on a substrate, and appropriate wirings 11 and 12 are provided. Reference numeral 3 denotes a support frame, and reference numeral 4 denotes a face plate. At a joint portion, they 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 this portion becomes an image display area. The phosphor film 7 is made of only a phosphor in the case of a display device for displaying a black and white image. However, when displaying a color image, the phosphor film 7 is composed of phosphors of three primary colors of red, green and blue. Call) is formed,
In some cases, the structure is separated by a black conductive material.
Black conductive material, depending on its shape, black stripe,
It is called a black matrix. Details will be described later.

The metal back 8 is formed of a conductive thin film of Al or the like. The metal back 8 converts the light, which has been emitted from the phosphor, that travels toward the electron source 1 into the glass substrate 6.
To improve the brightness by reflecting in the direction of
It also functions to prevent the gas remaining in the phosphor from damaging the phosphor due to the impact of ions generated by ionization by the electron beam. Further, it provides conductivity to the image display area of the face plate 4 to prevent charge from being accumulated, and serves as an anode electrode for the electron source 1. The metal back 8 is electrically connected to the high-voltage terminal Hv so that a voltage can be applied from outside the envelope 5 through the high-voltage terminal Hv.

On the wiring 12 (upper wiring), a non-evaporated non-evaporated plasma spraying method was used as a test object for maintaining the pressure in the envelope 5 and for inspecting the degree of vacuum in the envelope 5. A mold getter 2 is formed. As for the thickness of the getter film, the point of maintaining the exhaust capability for a long time, and the lower limit of the particle size of the powder material is determined in order to maintain the getter capability of the raw material powder and facilitate handling, so the film thickness after thermal spraying is also required. It is determined, and it is preferable that the film thickness is about 10 μm or more. Further, in order to prevent film peeling after thermal spraying, the thickness of the getter material is preferably 100 μm or less. As the getter material, a commonly used non-evaporable getter can be used. For example, metals such as Ti, Zr, Hf, V, Nb, Ta, and W and alloys thereof can be used. In particular, the present invention is characterized in that metal Zr is contained as a constituent element. . Further, the alloy may contain Al, Fe, Ni, Mn, or the like.

Since the surface of the sprayed film of the getter has irregularities of several μm to several tens μm, it has a larger surface area than the surface of the vapor-deposited film which is vacuum-deposited on a smooth surface, and therefore can have a higher pumping speed. .

In addition, a film having a thickness of about 10 to 100 μm can be easily formed in a short time in a single irradiation, and the life of the getter material can be extended by forming such a thick film. Can be.

FIG. 3 is a diagram showing an example of the arrangement of measurement terminals for measuring the resistance value of the non-evaporable getter used in the present invention. Since the measuring terminals 16 and 17 are used for monitoring the resistance value of the non-evaporable getter, it is possible to appropriately select a preferable material and terminal form as long as the object can be achieved. But Figure 3
However, the present invention is not limited to the embodiment shown in FIG.

In FIG. 1, reference numeral 11 denotes a row selection terminal for selecting a row of elements to emit electrons, and reference numeral 12 denotes a signal input for inputting a signal for controlling the amount of electron emission of the electron-emitting elements belonging to the selected row. Terminal. Note that the row selection terminal 11 is connected to the X-direction wiring in the electron source, and the signal input terminal 12 is connected to the Y-direction wiring. The form of these terminals is appropriately selected depending on the structure of the electron source 1 and the control method, and is not limited to the structure shown in FIG.

In some cases, an evaporable getter 10 (a ring-shaped getter is schematically shown in FIG. 1) is disposed in the envelope 5 as an auxiliary pump for keeping the interior of the envelope 5 at a vacuum.
In this case, the getter material is scattered in the image display area, and in order to prevent an electrical short circuit between the electrodes, the getter material is connected between the evaporable getter 10 and the area including the electron-emitting devices 13, the wiring groups 11, 12, and the anode electrode. , A shield 9 is provided. It should be noted that only the non-evaporable getter 2 formed on the wiring 12 is
If the inside can be kept sufficiently vacuum, the evaporable getter 10 and the shield 9 need not be formed.

Next, the structure of the above-described fluorescent film 72 will be described.

FIG. 7A shows a case where the phosphors 72 are arranged in a stripe pattern. The phosphors 72 of three primary colors of red (72R), green (72G), and blue (72B) are formed in order. Are separated by a black conductive material 71. In this case, the portion of the black conductive material 71 is called a black stripe.

FIGS. 7B to 7D show the arrangement of the dots of the phosphor 72 in a grid pattern, which are separated by a black conductive material 71. In this case, the black conductive material 71 is called a black matrix.

As a method of patterning the black conductive material 71 and the phosphor 72 on the glass substrate 6, a slurry method, a printing method, or the like can be used. After the fluorescent film 7 is formed,
A metal back 8 is formed.

The support frame 3 formed as described above,
The face plate 4 and the electron source 1 are joined. If the substrate of the electron source 1 alone cannot withstand the atmospheric pressure after evacuation, a spacer is disposed between the electron source 1 and the face plate 4 or a reinforcing plate is provided on the back surface of the electron source 1. May be combined. The joining is performed by attaching frit glass to the joining portion and heating to about 400 ° C. As an actual operation, a heat treatment at about 300 ° C. is performed in the air to remove components contained as a binder in the frit glass (this step is referred to as “temporary firing”), and then an inert gas such as Ar ( In an inert gas, a heat treatment at 400 ° C. is performed to weld the joint.

When the electron source 1 includes a surface conduction electron-emitting device, necessary processing such as forming and activation of the electron-emitting device is performed, and the inside of the envelope 5 is sufficiently evacuated.

Thereafter, the activation of the non-evaporable getter 2 is performed while monitoring the resistance value of the non-evaporable getter 2 using the resistance measuring terminals 16 and 17. As a method of monitoring the resistance value of the non-evaporable getter 2, the resistance measuring terminals 16 and 17 are used.
May be brought into contact with the non-evaporable getter 2, a predetermined voltage may be applied between the resistance measuring terminals, and a current value flowing between the terminals may be used.

The activation process of the non-evaporable getter 2 is usually carried out by heating at a high temperature in a vacuum. If the partial pressure of oxygen in the image forming apparatus becomes higher than a predetermined value during heating, the metal Zr, which is the main component of the non-evaporable getter 2, is oxidized and changes to an oxide. Since this change directly causes a change in the resistance value of the getter material, by monitoring the resistance value of the non-evaporable getter 2, it is possible to easily detect a decrease in the degree of vacuum in the container.

While operating this detecting means, the envelope 5
By heating the whole at a high temperature of about 350 ° C. for several hours to several tens of hours, the non-evaporable getter 2 on the wiring 12 is activated. If the non-evaporable getter 2
If the resistance value of the sample changes drastically or exceeds a predetermined threshold value (change from metal to oxide), heating is immediately stopped. Thereafter, a portion where a sealing defect (not completely sealed) has occurred is searched for, a repair operation is performed, and the activation process of the non-evaporable getter 2 is performed again. Then, when it is finally determined that there is no abnormality in the pressure in the image forming apparatus, the exhaust pipe (not shown) is heated and closed with a burner.

Finally, if necessary, the evaporable getter 10 (in the figure, a ring-shaped getter is schematically shown) provided in the envelope 5 is heated, and the getter material is attached to the inner wall of the envelope 5. Is deposited to form a getter material film. The getter film thus formed is located outside the image display area in the envelope 5.

As a final inspection of the image display apparatus, the resistance value of the non-evaporable getter 2 is measured again to complete the inspection of the degree of vacuum in the container of the image forming apparatus, and it is possible to obtain a non-defective product. Becomes

Next, NTS is performed by the above-described image forming apparatus.
An example of a structure of a driving circuit for performing television display based on a C-system television signal will be described with reference to FIG. 14, reference numeral 141 denotes an image forming apparatus (also referred to as a display panel) of the present invention, 142 denotes a scanning circuit, 143 denotes a control circuit, and 144 denotes a shift register. Also, 14
5 is a line memory, 146 is a synchronization signal separation circuit, 147
Is a modulation signal generator, and Vx and Va are DC voltage sources.

The image forming apparatus 141 has terminals _Dox1-Dox
oxm , terminals _{Doy1 to Doyn} , and a high voltage terminal Hv are connected to an external electric circuit. Terminals D _{ox1 -D
oxm} is a scanning device for sequentially driving electron sources provided in the image forming apparatus, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns, one row at a time (n elements). A signal is applied.

To the terminals _{Doy1 to Doyn} , a modulation signal for controlling an output electron beam of each of the surface conduction electron-emitting devices in one row selected by the scanning signal is applied. The high-voltage terminal Hv is connected to the DC voltage source Va, for example, by one.
A DC voltage of 0 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 142 will be described. Scanning circuit 142 are those having the m-number of switching devices therein (in the figure, is schematically shown in S ₁ to S _m).
Each switching element selects either the output voltage of the DC voltage source Vx or 0 V (ground level),
The terminals D _{ox1 to} D _oxm of the image forming apparatus 141 are electrically connected. Each switching element S ₁ to S _m, which operates based on a control signal T _scan control circuit 143 outputs, it can be configured by combining switching elements such as FET.

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 device which is not scanned is the electron emission threshold. It is set to output a constant voltage that is equal to or lower than the value voltage.

The control circuit 143 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. This control circuit 143
Is the synchronization signal T sent from the synchronization signal separation circuit 146.
Based on the _sync , T _scan and T _sft and T _mry control signals are generated for each unit.

The synchronizing signal separation circuit 146 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC system television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 146 includes 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 144.

The shift register 144 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image. The shift register 144 receives the control signal _Tsft sent from the control circuit 143. (Ie, the control signal _Tsft is a shift clock of the shift register 144).
The data for one line of the serial / parallel-converted image (corresponding to the drive data for n electron-emitting devices) is I _d1
To _{Idn as} the n parallel signals.
4 is output.

The line memory 145 is a storage device for storing data for one line of an image for a required time.
In accordance with the control signal T _mry sent from the control circuit 143 stores the contents of the appropriate I _d1 ~I _dn. The stored contents are output as I _{d′ 1 to} I _{d′ n} , and the modulated signal generator 1
47 is input.

The modulation signal generator 147 outputs the image data I
_d'1 is ~I signal source for properly driving modulating each of the surface conduction electron-emitting device according to each of _d'n, the output signal through a terminal _D oy1 ~D oyn, an image forming apparatus 141 is applied to the surface conduction electron-emitting device.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current _Ie . That is, a clear threshold voltage V is required for electron emission.
_th There is, only electron emission when it is applied to the V _th or more of voltage occurs. 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. From this, when applying a pulsed voltage to this element,
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, an electron beam is output. At this time, by varying the peak value V _m of pulse, it is possible to control the intensity of the output electron beam. Also, the pulse width P
By changing _w , 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, a circuit of a voltage modulation method that generates a voltage pulse of a fixed length and modulates the peak value of the pulse appropriately according to input data is used as the modulation signal generator 147. be able to.

When implementing the pulse width modulation method,
As the modulation signal generator 147, a pulse width modulation type 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 144 and the line memory 14
5 can be 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 synchronization signal separation circuit 146 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 146. Just do it. In this connection, the circuit used for the modulation signal generator 147 differs slightly depending on whether the output signal of the line memory 145 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 14
For example, a D / A conversion circuit is used in 7 and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 147 includes, for example, a high-speed oscillator and a counter for counting the number of waves output from the oscillator, and a comparison for comparing the output value of the counter with the output value of the memory. The circuit which combined the device (comparator) is used. If necessary, an amplifier for voltage-amplifying the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier can be used as the modulation signal generator 147, and a level shift circuit and the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage-controlled oscillation circuit (VOC) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the surface conduction electron-emitting device can be added as necessary.

In the image forming apparatus of 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 ~D oyn, electron emission occurs. And the high voltage terminal Hv
A high voltage is applied to the metal back 8 via the, and the electron beam is accelerated. The accelerated electrons collide with the fluorescent film 7 and emit 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 concept of the present invention. For example, the input signal is described in the NTSC system. However, the input signal is not limited to the NTSC system. In addition to the PAL and SECAM systems, a TV signal including a larger number of scanning lines (for example, MUSE system and the like) High-definition TV system).

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.

[0076]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to preferred examples, but the present invention is not limited to these examples, 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> An image forming apparatus inspected and prepared by the method of inspecting the degree of vacuum inside the image forming apparatus according to the present embodiment has the same configuration as the apparatus schematically shown in FIG. A plurality of (100 rows × 300 columns) surface conduction electron-emitting devices are arranged in a simple matrix wiring.

FIG. 3 is a plan view of a part of the electron source 1. FIG. 4 is a sectional view taken along the line AA 'in FIG. In FIGS. 3 and 4, members having the same functions are denoted by the same reference numerals and described.

Here, 51 is an electron source substrate, 52 is an X-direction wiring corresponding to _Doxm in FIG. 1, 53 is a Y-direction wiring corresponding to _Doyn in FIG. 1, 54 is a surface conduction electron-emitting device,
5 is a non-evaporable getter, 61 is an interlayer insulating layer, 62 and 63 are device electrodes, 64 is a conductive film including an electron emission portion, and 65 is a device for electrically connecting the device electrode 63 and the Y-direction wiring 53. It is a contact hole.

FIGS. 1, 2, 5, and 6 show a method of manufacturing and an inspection method of the image forming apparatus according to the present embodiment.
This will be described with reference to FIG. Step-a 5 nm-thick Cr and 600 nm-thick Au were sequentially laminated by vacuum evaporation on an electron source substrate 51 in which a 0.5 μm-thick silicon oxide film was formed on a cleaned blue plate glass by a sputtering method. Thereafter, a photoresist (AZ1370 Hoechst) is spin-coated with a spinner and baked, and then a photomask image is exposed and developed to form a Y-directional wiring 5.
A resist pattern 3 is formed, and the Au / Cr deposited film is wet-etched to form a Y-directional wiring 53 having a desired shape (FIG. 5A). Step-b Next, an interlayer insulating layer 61 made of a silicon oxide film having a thickness of 1.0 μm is deposited by an RF sputtering method (FIG. 5).
(B)). Step-c A photoresist pattern for forming the contact hole 65 is formed in the silicon oxide film deposited in the step b, and the interlayer insulating layer 61 is etched using the photoresist pattern as a mask to form the contact hole 65. Etching is CF
RIE (Reactive Io) using ₄ and H ₂ gas
n Etching) method (FIG. 5 (c)). Step-d After that, a pattern to be the element electrodes 62 and 63 and the element electrode interval G is formed by a photoresist (RD-200N-41).
Hitachi Chemical Co., Ltd.) and a thickness of 5 n
m of Ti and 100 nm of Ni were sequentially deposited. The photoresist pattern was dissolved with an organic solvent, the Ni / Ti deposited film was lifted off, and the device electrodes 62 and 63 were formed with the device electrode interval G of 3 μm and the device electrode width of 300 μm (FIG. 5D). Step-e After forming a photoresist pattern of the X-direction wiring 52 on the device electrodes 62 and 63, 5 nm thick Ti and 500 nm thick Au are sequentially deposited by vacuum deposition, and unnecessary Remove the part to get the desired shape of X
The direction wiring 52 was formed (FIG. 6E). Also, the resistance measuring terminals 16 and 17 can be formed simultaneously with this step. The resistance measuring terminals 16 and 17 are 500 nm thick A
u. Step-f A Cr film 66 having a thickness of 100 nm is deposited and patterned by vacuum evaporation, and a Pd amine complex solution (ccp
4230 Okuno Pharmaceutical Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes.

The thus formed conductive film 64 for forming an electron emitting portion composed of fine particles of Pd as the main element has a thickness of 8.7 nm and a sheet resistance of 3.2 ×.
It was 10 ⁴ Ω / □. (FIG. 6 (f)). Step-g A desired pattern was formed by etching the Cr film 66 and the conductive film 64 for forming the electron emission portion after firing with an acid etchant (FIG. 6G). Step-h A pattern is formed such that a resist is applied to portions other than the contact hole 65, and a 5 nm-thick T
i, Au having a thickness of 500 nm was sequentially deposited. Unnecessary portions were removed by lift-off to bury the contact holes 65 (FIG. 6H).

Through the above steps, a plurality of (100 rows × 300 columns) conductive films 64 for forming electron-emitting portions were formed on the electron source substrate 51 by simple matrix wiring using the X-directional wiring 52 and the Y-directional wiring 53. An electron source 1 was formed. Step-i Next, a face plate 4 serving as an image display portion was prepared. In the face plate 4, a transparent electrode (not shown) made of ITO was provided on the glass substrate 6 in order to increase the conductivity of the fluorescent film 7. The fluorescent film 7 serving as an image forming member is a stripe-shaped phosphor (see FIG. 7A) in order to realize a color, a black stripe is formed first, and each color is formed by a slurry method in a gap. The phosphors 72R, 72G, and 72B were applied to form the phosphor film 7. As a material for the black stripe, a material mainly containing graphite, which is commonly used, was used.

Further, a metal back 8 was provided on the inner surface side of the fluorescent film 7. The metal back 8 was manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 7 after the fluorescent film 7 was manufactured, and then performing vacuum deposition of Al. Step-j Next, a non-evaporable getter was formed on the Y-direction wiring 53 and in the area of the resistance measurement terminals 16 and 17.

The non-evaporable getter was formed by thermal spraying. In the thermal spraying, the electron source substrate 51 is mounted in a low-pressure plasma spraying apparatus (7MC type manufactured by Sulzer Metco), and a non-evaporable getter material (Zr (75%)-V (20%)-Fe) is used.
(5%) alloy powder # 325 mesh). At this time, the pressure inside the pressure reducing tank is once reduced to 1.3 × 10 Pa, and then the pressure inside the tank is reduced to 4.7 × 10 ³ Pa with Ar gas.
And spraying was performed. After the thermal spraying, the pressure in the tank was again reduced to 1.3 × 10 Pa, and then nitrogen gas was introduced to the atmospheric pressure. After the temperature of the non-evaporable getter was sufficiently lowered, the tank was opened to the atmosphere and taken out. The thickness of the formed getter material was about 40 μm on average. Step-k Next, the envelope 5 shown in FIG. 1 was manufactured by the following procedure.

The electron source 1 created by the above-described steps
The support frame 3, the shield 9, the ring-type evaporable getter 10, and the face plate 4 are combined, and the positions of the electron source 1 and the phosphors of each color of the face plate 4 are strictly adjusted. Was formed. The sealing method is as follows: frit glass is applied to the joint portion, and calcined at 300 ° C. in the air.
Heat treatment was performed at 0 ° C. for 10 minutes to perform bonding.

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

In FIG. 2, reference numeral 42 denotes a gate valve, which separates the image forming apparatus 30 side (area A in the figure) from the other vacuum processing system and gas introduction control system (area B in the figure). . By exchanging the A area, the system in the B area
It can be used for other image forming apparatuses. 31 is an exhaust pipe. Further, the vacuum chamber 32 is connected to a gate valve 33, and the gate valve 33 is connected to the exhaust device 3.
4. The exhaust device 34 is configured by a backup dry pump connected to a magnetic levitation type turbo molecular pump via a valve (not shown).

The vacuum chamber 32 has a pressure gauge 35 for monitoring the internal pressure and a quadrupole mass spectrometer (Q-ma) for monitoring the gas partial pressure inside the vacuum chamber 32.
ss) 36 is provided. Furthermore, vacuum chamber 3
Numeral 2 is connected to an ampule 40 and a cylinder 41 in which an introduced substance source 39 is sealed, via a gas introduction line 37 and a gas introduction control device 38 provided in the middle of the gas introduction line 37. In the present embodiment, a variable leak valve compatible with ultra-high vacuum was used as the gas introduction control device 38, and the ampoule 40 was equipped with acetone (CH ₃ ) ₂ CO. The following steps were performed using the above vacuum processing apparatus and inspection apparatus. Step-1 The gas in the envelope 5 completed in the previous step is exhausted by the exhaust device 34 through the exhaust pipe 31 and the vacuum chamber 32, and reaches about 1 × 10 ⁻³ Pa as indicated by the pressure gauge 35. After that, FIG.
The forming was performed using the apparatus shown in FIG.

FIG. 8 is a schematic view of an apparatus for applying a voltage to the image forming apparatus under the manufacturing process in the forming process. In this embodiment, the device is used also in the subsequent activation process.

As shown in FIG. 8, the image forming apparatus 30 under the manufacturing process connects the Y-direction wirings D _{y1 to} D _yn and connects them to the ground, while the X-direction wirings D _{x1 to} D _xm Each is connected to a corresponding terminal of the switching box 104. Reference numeral 101 denotes a control device, which is a pulse generator 10.
2. The switching box 104 is controlled through a control signal bus, and the measured value measured by the ammeter 103 is obtained through a measurement data transfer bus.

The switching box 104 selects one line from the X-direction wirings D _{x1 to} D _xm , and _supplies the selected line to the pulse generator 102 through the ammeter 103.
Is applied. The unselected lines are connected to the ground potential by the switching box 104. The forming process was performed for each element row in the X direction (300 elements).

The waveform of the applied pulse was a rectangular pulse as shown in FIG. 9A, and the peak value (peak of the voltage difference between the element electrodes) was gradually increased from 0V. Note that the pulse width T ₁ = 1 msec and the pulse interval T ₂ = 10 msec.

Further, a peak value of 0.1 is applied between rectangular wave pulses.
A rectangular wave pulse of V was inserted (FIG. 9B), and the resistance of each row was measured by measuring the current. 3.3k resistance
When it exceeded Ω (1 MΩ per element), the forming of that row was terminated, and the process proceeded to the next row. This process is performed for all the rows to complete the forming of all the conductive films (the conductive films 64 for forming the electron emission portions), to form the electron emission portions in each of the conductive films, and to form a plurality of surface conduction type electrons. An electron source 1 in which emission elements were wired in a simple matrix was prepared. Step-m Next, acetone (CH ₃ ) ₂ CO
And adjusted so that the indicated value of the pressure gauge 35 becomes about 2 × 10 ⁻³ Pa. At that time, it is confirmed that the gas molecules of acetone are surely introduced into the vacuum chamber 32 by using the Q-mass 36.

Then, similar to the forming step, FIG.
By applying a pulse voltage through each of the X-direction wirings using the device described above, the activation process of each electron-emitting device was performed. The pulse waveform generated by the pulse generator 102 is
The rectangular wave shown in FIG. 9A has a peak value of 15 V, a pulse width T ₁ = 1 msec, and a pulse interval of 100 msec. The switching box 104, repeating to switch sequentially select line for each 1msec to D _x1 to D _x100, this result, in each element row, T ₁ = 1mse
c, a rectangular wave of T ₂ = 100 msec is applied with the phase slightly shifted for each row (FIG. 10).

The ammeter 103 is used in a mode for detecting the current value in the ON state of the rectangular wave pulse (when the voltage is 15 V), and the average of the current value in each element row is 600 mA (2 mA per element). ), The pulse application was terminated, the inside of the envelope 5 was evacuated, and the activation process was terminated. Step-n It is assumed that the whole of the image forming apparatus 30 and the vacuum vessel 32 is maintained at 200 ° C. for 5 hours by a heating device (not shown) while being evacuated, and is adsorbed on the envelope 5 and the inner wall of the vacuum chamber 32. Possible (CH ₃ ) ₂ CO and its decomposition products were once evacuated.

Then, by applying a predetermined voltage between the resistance measuring terminals 16 and 17, the current flowing between the resistance measuring terminals 16 and 17 is measured, and the resistance value of the non-evaporable getter 57 (shown in FIG. 3) is measured. Started monitoring. Then, the temperature was maintained at 350 ° C. for 10 hours to further remove the residual adsorbed gas molecules and activate the non-evaporable getter material. Step-o In the evacuation process, it was confirmed that the change in the resistance value of the non-evaporable getter 57 did not change beyond a certain threshold. Then, after confirming that the pressure was 1.3 × 10 ⁻⁵ Pa or less, the exhaust pipe was heated with a burner and sealed. Subsequently, the evaporable getter 10 previously set outside the image display area was flashed by high-frequency heating.

Finally, when the image display device is completed, the resistance of the non-evaporable getter 57 is measured again to confirm that there is no abnormality. Was judged to be good.

<Example 2> At the stage -e in Example 1, Au having a thickness of 500 nm was formed with the shape of the resistance measuring terminal as shown in FIG. In this embodiment, a normal four-terminal method is used as a method for measuring the resistance of the non-evaporable getter.

In FIG. 15, members having the same functions as those in FIG. 3 are denoted by the same reference numerals.

Thereafter, the same steps as those in the first embodiment are performed, and then, the forming and activation steps are performed in the same manner as in the first embodiment. The entire device 30 and vacuum vessel 32
It was kept at 0 ° C. for 5 hours.

Thereafter, the resistance value of the non-evaporable getter 57 was monitored using the resistance measuring terminal 16. And
By maintaining the temperature at 350 ° C. for 10 hours, the remaining adsorbed gas molecules were further removed, and the non-evaporable getter material provided in the image forming apparatus was activated.

In the evacuation process, the non-evaporable getter 5
It was confirmed that the change in the resistance value of No. 7 did not change beyond a certain threshold value. Then, after confirming that the pressure was 1.3 × 10 ⁻⁵ Pa or less, the exhaust pipe was heated with a burner and sealed. Subsequently, the evaporable getter 10 previously set outside the image display area was flashed by high-frequency heating.

Finally, in a state where the image display device is completed, the resistance value of the non-evaporable getter 57 is measured again to confirm that there is no abnormality. Was judged to be good.

By using the resistance measuring method of the present embodiment, the resistance value can be monitored more accurately than in the case of the first embodiment.

<Embodiment 3> At the step e in the embodiment 1, the resistance measuring terminal was shaped as shown in FIG. 16 and Au having a thickness of 500 nm was arranged on all sides of the panel.

In FIG. 16, members having the same functions as those in FIG. 3 are denoted by the same reference numerals. In FIG. 16, reference numerals 161 to 168 denote resistance measuring terminals provided with a non-evaporable getter 57 provided for detecting the degree of vacuum.

Thereafter, the same steps as those in the first embodiment are performed, and then the forming and activation steps are performed in the same manner as in the first embodiment. The entire device 30 and vacuum vessel 32
It was kept at 0 ° C. for 5 hours.

Thereafter, the resistance measuring terminals 16 in each region,
17, the resistance value of the non-evaporable getter 57 was monitored. By maintaining the temperature at 350 ° C. for 10 hours, the remaining adsorbed gas molecules were further removed, and the non-evaporable getter material provided in the image forming apparatus was activated.

In the evacuation process, the non-evaporable getter 5
It was confirmed that the change in the resistance value of No. 7 did not change beyond a certain threshold value. Thereafter, the pressure is 1.3 × 10 ⁻⁵ Pa
After confirming the following, the exhaust pipe was heated with a burner and sealed. Subsequently, the evaporable getter 10 previously set outside the image display area was flashed by high-frequency heating.

Finally, when the image display device is completed, the resistance value of the non-evaporable getter 57 is measured again to confirm that there is no abnormality. Was judged to be good.

According to the resistance measuring method of this embodiment, the monitoring place (the non-evaporable getter 5) is different from the method of the first embodiment.
7, the resistance can be measured more accurately.

[0112]

As described above, according to the image forming apparatus and the method of inspecting the degree of vacuum inside the image forming apparatus according to the present invention, the final stage of the manufacturing process of the image forming apparatus is as follows.
It is possible to detect the degree of vacuum on the image forming apparatus side before performing sealing on the image forming apparatus side and the vacuum processing apparatus system side.

Therefore, when an abnormality of the degree of vacuum or the like occurs in the manufacturing process of the image forming apparatus, it can be repaired in advance, and the image forming apparatus can be assembled without waste. Useless use is eliminated, and manufacturing costs can be reduced.

Further, the method for inspecting the degree of vacuum in the image forming apparatus according to the present invention can be easily applied to the final inspection of the degree of vacuum in the image forming apparatus. A method could be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of an image forming apparatus with an inspection mechanism to which the present invention can be applied.

FIG. 2 is a schematic diagram illustrating an outline of a vacuum processing apparatus and an inspection apparatus used for manufacturing an image forming apparatus.

FIG. 3 is a schematic diagram showing the positional relationship between the arrangement of the electron source and the non-evaporable getter of the present invention and the resistance measuring terminal.

FIG. 4 is a sectional view taken along line A-A 'of the electron source shown in FIG.

FIG. 5 is a schematic view for explaining a manufacturing process of the electron source shown in FIG.

FIG. 6 is a schematic view for explaining a manufacturing process of the electron source shown in FIG.

FIG. 7 is a schematic diagram for explaining a structure of a fluorescent film.

FIG. 8 is a schematic diagram illustrating a configuration of an apparatus used for a manufacturing process, a forming process, and an activation process of the image forming apparatus.

FIG. 9 is a diagram illustrating an example of a pulse voltage waveform applied to a forming process.

FIG. 10 is a diagram showing a pulse voltage waveform applied to each X-direction wiring and a temporal relative relationship during an activation process.

FIG. 11 is a schematic diagram showing a configuration of an electron source having a matrix wiring electron source used for explaining a conventional technique.

FIG. 12 is a schematic diagram showing an example of an image forming apparatus using the electron source of FIG.

FIG. 13 is a schematic plan view (A) and a schematic cross-sectional view (B) showing the configuration of a surface conduction electron-emitting device used in the description of the conventional technique.

FIG. 14 is a block diagram illustrating a configuration example of a driving circuit for performing television display based on an NTSC television signal by an image forming apparatus configured using an electron source in a matrix arrangement.

FIG. 15 is a schematic diagram illustrating a positional relationship between the arrangement of a non-evaporable getter and a resistance measuring terminal, which will be described in a second embodiment.

FIG. 16 is a schematic diagram showing a positional relationship between the arrangement of a non-evaporable getter and a resistance measuring terminal, which will be described in a third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electron source 2 Non-evaporable getter 3 Support frame 4 Face plate 5 Enclosure 6 Glass substrate 7 Fluorescent film 8 Metal back 9 Shield 10 Evaporative getter 11 Row selection terminal 11 'X-direction wiring 12 Signal input terminal 12' Y direction wiring 13 Surface conduction type electron-emitting device 14 Electron source substrate 15 Rear plate 16, 17 Resistance measurement terminal 30 Image forming device 31 Exhaust pipe 32 Vacuum chamber 33 Gate valve 34 Exhaust device 35 Pressure gauge 36 Q-Mass 37 Gas introduction line Reference Signs List 38 gas introduction control device 39 introduction substance source 40 ampoule 41 cylinder 42 gate valve 51 electron source substrate 52 X-direction wiring 53 Y-direction wiring 54 surface conduction electron-emitting device 55 non-evaporable getter 56 connection 57 for detecting the degree of vacuum Non-evaporable getter provided 61 Interlayer insulating layer 62, 63 element Child electrode 64 Conductive film including electron-emitting portion 65 Contact hole 66 Cr film 71 Black conductive material 72R, 72B, 72G Phosphor 101 Controller 102 Pulse generator 103 Ammeter 104 Switching box 131 Substrate 132, 133 Element electrode 134 Conductive Conductive thin film 135 Electron emission section 141 Display panel 142 Scanning circuit 143 Control circuit 144 Shift register 145 Line memory 146 Synchronous signal separation circuit 147 Modulation signal generator 161 to 168 Resistance measurement terminal

Claims (12)

[Claims] 1. An electron source having a plurality of electron-emitting devices disposed on a substrate in an envelope, an image forming member disposed to face the substrate, and a degree of vacuum inside the envelope. An image forming apparatus having a getter material for maintaining the condition, wherein a vacuum degree detecting means for detecting a degree of vacuum inside the image forming apparatus based on a change in resistance value of the getter material is provided. Image forming device. 2. An electron source in which a plurality of electron-emitting devices are disposed on a substrate in an envelope, an image forming member disposed to face the substrate, and a degree of vacuum inside the envelope. An image forming apparatus having a getter material for maintaining a vacuum degree, wherein a vacuum degree detecting means for detecting a degree of vacuum inside the image forming apparatus based on a change in resistance value of a non-evaporable getter material formed by a thermal spraying method An image forming apparatus comprising: 3. The image forming apparatus according to claim 2, wherein the non-evaporable getter material contains metal Zr as a constituent element. 4. The image forming apparatus according to claim 2, wherein the thickness of the non-evaporable getter material formed by the thermal spraying method is 10 to 100 μm. 5. The image forming apparatus according to claim 1, wherein said electron source is an electron source in which a plurality of electron-emitting devices arranged in a matrix are arranged on a substrate. apparatus. 6. The image forming apparatus according to claim 1, wherein said electron source has a surface conduction electron-emitting device. 7. An electron source in which a plurality of electron-emitting devices are disposed on a substrate in an envelope, an image forming member disposed to face the substrate, and a degree of vacuum in the envelope. A method for inspecting a degree of vacuum inside an image forming apparatus having a getter material for maintaining the degree of vacuum, wherein the degree of vacuum inside the image forming apparatus is detected based on a change in a resistance value of the getter material. Inspection method for the degree of vacuum inside the image forming apparatus. 8. An electron source in which a plurality of electron-emitting devices are arranged on a substrate in an envelope, an image forming member arranged to face the substrate, and a degree of vacuum inside the envelope. A method for inspecting the degree of vacuum inside the image forming apparatus having a getter material for maintaining the temperature, wherein a change in the resistance value of the non-evaporable type getter material formed by a thermal spraying method is performed based on a change in the resistance value. A method for inspecting the degree of vacuum inside an image forming apparatus, wherein the degree of vacuum is detected. 9. The method for inspecting a degree of vacuum inside an image forming apparatus according to claim 8, wherein the non-evaporable getter material contains metal Zr as a constituent element. 10. The method according to claim 8, wherein a thickness of the non-evaporable getter material formed by the thermal spraying method is 10 to 100 μm. 11. The image forming apparatus according to claim 7, wherein said electron source is an electron source in which a plurality of electron-emitting devices arranged in a matrix are arranged on a substrate. Inspection method for the degree of vacuum inside the device. 12. The method according to claim 7, wherein the electron source includes a surface conduction electron-emitting device.