JP2005332698A - Image formation device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long-life image formation device hardly generating discharge during operation and capable of preventing generated ions from easily damaging a cold-cathode electron emission element, in an image formation device using the cold-cathode electron emission element. <P>SOLUTION: This image formation device is composed by forming an evacuation space by sealing, through a joint material, a display panel 132 having a phosphor screen, and a back panel 131 having a cold-cathode electron emission element array facing to the display panel 132 for emitting an electron beam. In the evacuation space, a gas comprising at least one kind of He, Ne and Ar, or the gas and either Kr gas or Xe gas are/is introduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and a method for manufacturing the image forming apparatus.

  In image forming apparatuses, in recent years, a shift to a flat panel display that is lighter and thinner than a conventional cathode ray tube (hereinafter referred to as “CRT”) and can be enlarged is progressing, and plasma displays and liquid crystal displays have been commercialized. Market penetration is also progressing rapidly. In the future, in addition to thin and lightweight, development is expected to progress to large displays that have both high image quality and low power consumption. Under such circumstances, displays using cold cathode electron-emitting devices are promising as large-scale displays that have both high image quality and low power consumption and are cheaper than plasma displays and liquid crystal displays.

  Cold cathode electron-emitting devices include field emission type (hereinafter referred to as “FE type”), metal / insulating layer / metal type (hereinafter referred to as “MIM type”), surface conduction type (hereinafter referred to as “SC type”), and the like. There is. As examples of the FE type, those disclosed in Non-Patent Document 1, Non-Patent Document 2, and the like are known. As an example of the MIM type, one disclosed in Non-Patent Document 3 or the like is known. Examples of the SC type include those disclosed in Non-Patent Document 4 and the like.

  The structure and operating principle of the MIM type cathode are shown below. FIG. 2 shows the structure of the MIM type cathode. The basic structure is a three-layer thin film in which a lower electrode 9, a tunnel insulating film 14, and an upper electrode 8 are laminated. When a voltage of about 10 V is applied between the lower electrode 9 and the upper electrode 8, electrons are emitted from the entire surface of the upper electrode. In addition, it has a field insulating film 4 that prevents electric field concentration on the lower electrode edge, a contact electrode 5 that serves as a power supply line to the upper electrode 8, and a bus electrode 6. The protective insulating layer 7 protects the cathode wiring from the mechanical contact of the spacer. The operation principle of the MIM type cathode will be briefly described. When a high electric field is applied to the insulating layer 14 between the lower electrode 9 and the upper electrode 8, electrons are injected into the insulating layer by the Fowler-Nordheim tunnel phenomenon. These electrons are accelerated in the insulating layer and become hot electrons. A part of it reaches the surface of the upper electrode, and electrons having energy and momentum exceeding the work function barrier are emitted into the vacuum.

  The outline of the cathode manufacturing process and paneling process of the MIM type cathode flat display will be described below. 3 and 4 show the process of the MIM type cathode. An Al-2 atomic% Nd alloy film is formed on the soda glass substrate 1 covered with the SiNx / SiO 2 undercoat film by sputtering, and the lower electrode (row electrode) 9 is formed. Next, the field insulating layer 4 is formed by anodic oxidation through the resist 15, and then the tunnel insulating layer 14 is formed by anodic oxidation (FIGS. 3A and 3B). Subsequently, a laminated bus electrode of the W film 6 and the Al—Nd alloy film 5 is formed by sputtering and formed into a column electrode by wet etching, and then a protective insulating layer 7 of SiNx is formed (FIG. 3C). Thereafter, the electron emission portion is opened by plasma etching and wet etching (FIG. 4A). Thereafter, an Ir—Pt—Au laminated film 8 for the upper electrode is formed and completed (FIG. 4B). In the final process, since the protective insulating film serves as a mask and the upper electrode is self-aligned, etching or the like is unnecessary. Therefore, the number of masks can be reduced, and a high emission current can be obtained without contaminating the cathode surface with a resist. The undercoat films 2 and 3 prevent Na diffusion during baking of the panel seal (430 ° C.) and minimize the thermal stress on the Al—Nd film. The tunnel insulating film 14 is formed by anodic oxidation. Anodization allows film thickness to be controlled by formation voltage and oxidation rate to be controlled by formation current, and defect-free film with extremely high film thickness uniformity can be easily formed, making it ideal for display manufacturing that requires a large area and defect-free film. Insulating film formation method.

  On the phosphor screen of the front panel, an RGB pattern of BM and P22 phosphors is formed by a photo process similar to CRT, and an Al film having a thickness of 75 nm is deposited to serve as an anode acceleration electrode. The front panel and the rear panel are sealed at 430 ° C. using frit glass through a frame glass having a height of 3 mm. After sealing, the panel is evacuated from an exhaust pipe provided on the rear panel while heating to 350 ° C., and the chip is turned off.

In the sealing and exhausting process, as shown in Patent Document 1, sufficient degassing processing is performed by heat-treating the front panel and the back panel in the evacuated chamber, and then sealing is performed in the same chamber. In addition, Patent Document 2 discloses a manufacturing method in which exhaust processing, heating exhaust processing, sealing processing, and the like are performed in different chambers. It has been shown that when a plasma generating element is used instead, an inert gas such as argon gas or neon gas or hydrogen gas is contained under reduced pressure. Patent Document 3 discloses a manufacturing method in which a sufficient degassing process is performed by heat-treating the front panel and the back panel in a vacuum-evacuated chamber, and then sealing is performed in the same chamber. When a field emission type cold cathode electron-emitting device (FE type) is used, hydrogen is introduced from the gas introduction tube before sealing, and the hydrogen is left in the sealed vacuum vessel, and electrons are generated by oxidation of the emitter. It has been shown that deterioration over time of the release characteristics can be suppressed, and the partial pressure of hydrogen is preferably about 10 ⁻⁷ to 10 ⁻³ mbar.
Japanese Patent No. 3332906 JP 2001-229828 A JP 2001-35374 A W. P. Dyke & W. W. Dolan, “Field Emission”, Advance in Electron Physics, 8, 89 (1956). C. A. Spint, “PHYSICAL Properties of thin-film field emissions with mole denden cones”, J. Am. Appl. Phys. , 47, 5248 (1976) C. A. Mead, “Operation of Tunnel-Emission Devices”, J. Am. Appl. Phys. , 32, 646 (1961) M.M. I. Elinson, Radio Eng. Electron Phys. , 10, 1290 (1965)

However, the conventional image forming apparatus using the cold cathode electron-emitting device may cause the following problems.
(1) In the operation of the image forming apparatus, a voltage of usually 2 to 3 kV is applied to the anode electrode of the front panel, and the driving voltage corresponding to the driving signal is applied from the cold cathode electron emitting device disposed on the rear panel. Electrons are emitted by being applied to, and the emitted electrons are accelerated by the anode voltage, collide with the phosphor screen formed on the front panel, and emit phosphors corresponding to the respective colors. The space formed by the front panel, the back panel, and the frit is usually maintained at a vacuum level of 10 ⁻⁵ Pa or less by using a getter. However, discharge sometimes occurs during operation and is generated in the space. The damaged ions cause damage to the cold cathode electron-emitting device, resulting in uneven brightness. When the damage becomes fatal, electron emission may not occur. This phenomenon is that even in a high vacuum of about 10 ⁻⁵ Pa, residual gas such as CO and CO ₂ is present in the space, and the degree of vacuum is 2 when the space height is 3 mm and the mean free path is 3 mm. because it is .5 × 10 -4 ^Pa, electrons emitted if the degree of vacuum 2.5 × less than 10 -4 ^Pa performs linear acceleration motion to the anode electrode without colliding with the gas molecules, the anode electrode or fluorescent It collides with the body surface and its kinetic energy moves instantaneously. Since a voltage of 2 to 3 kV is normally applied to the anode electrode, the maximum energy of electrons is 2 to 3 keV. When electrons have exercise is stopped by collision bremsstrahlung occurs, CO, residual gases such as CO ₂ is ionized into positive ions in the braking radiant energy, the cold cathode the positive ions from the anode electrode side It is considered that the electron-emitting device was accelerated and damaged the cold-cathode electron-emitting device.

(2) In a large image forming apparatus, a rear panel on which a plurality of cold cathode electron-emitting devices are formed and a front panel on which a phosphor or the like is formed are positioned so as to maintain a desired relative position. After being temporarily fixed in combination at a predetermined distance, the temperature is raised to a temperature at which an adhesive member such as frit glass is softened and pressed to form a vacuum envelope. Since the distance is small and the conductance with respect to gas is small, it is very difficult to exhaust to a sufficient degree of vacuum through the exhaust pipe attached to the conventional back panel side in the exhaust process in the image forming apparatus following the sealing process. If the evacuation process takes a long time or completes in a short time, the degree of vacuum in the apparatus is poor or pressure unevenness occurs. As a result, the degree of vacuum necessary for stable electron emission characteristics is obtained. It may not.

  Further, the relative arrangement of the cold cathode electron-emitting device and the phosphor requires high positional accuracy in order to prevent color misregistration, etc., but the position due to thermal expansion in the sealing process and softening of the frit glass used for sealing. In some cases, the required positional accuracy could not be obtained due to misalignment or the like. After performing the sealing process, water, carbon monoxide, carbon dioxide, hydrogen, etc. are adsorbed on the front panel or back panel to stabilize the electron emission characteristics and prevent discharge due to the remaining gas. Therefore, it is necessary to remove the adsorbed gas and the like, and for that purpose, a step of exhausting the vacuum envelope through the exhaust pipe while baking the vacuum envelope is necessary after the sealing step. However, in this process, since the conductance of the container and the exhaust pipe with respect to the gas is small, the gas generated from the member cannot always be exhausted sufficiently, resulting in uneven brightness and a decrease in life.

  Furthermore, it is desirable to provide a method for manufacturing an image forming apparatus that solves these problems and does not cause recontamination due to re-adsorption of water, oxygen, hydrogen, carbon monoxide, carbon dioxide, etc. to each degassed member. It was.

  An object of the present invention is to provide an image forming apparatus in which the above problems have been solved, and a method for manufacturing the image forming apparatus.

  The present invention solves the problem that discharge sometimes occurs during operation, and the generated ions damage the cold cathode electron-emitting device to cause luminance unevenness, and when the damage becomes fatal, electron emission does not occur. And a manufacturing method of the image forming apparatus.

In the present invention, a display (front) panel having a phosphor screen and a back panel having a cold cathode electron-emitting device array that emits an electron beam facing the display panel are sealed with a bonding material. A gas composed of at least one of He, Ne, Ar, Kr, and Xe is introduced into the exhaust space. When the cold cathode electron-emitting device is an MIM type cold cathode electrode, a gas composed of at least one of He, Ne, Ar, Kr, Xe, and H ₂ is introduced into the sealing space. The partial pressure of the introduced gas is preferably set to be 10 ⁻¹¹ Pa or more and 10 ⁻² Pa or less. If the gas partial pressure is less than 10 ⁻¹¹ Pa, the time for evacuation becomes too long, which is not practical. When the gas partial pressure is higher than 10 ⁻² Pa, it is easier to discharge when the gas of the present invention is introduced, and scattering and trapping by the gas before the emitted electrons from the cold cathode electron-emitting device reach the anode electrode. As a result, the anode current is reduced and the brightness is lowered. A more preferable gas partial pressure range is 10 ⁻⁹ Pa or more and 10 ⁻³ Pa or less, and further preferably 10 ⁻⁸ Pa or more and 10 ⁻⁴ Pa or less.

In the present invention, the gas is introduced through the production method described below.
(1) In the vacuum chamber, the display panel and the back panel are held between the first heating unit and the second heating unit in a state where the sealing portion is not in contact, and the vacuum exhaust in the vacuum chamber is performed. A heating step of heating the display panel, the back panel, and the bonding material to a sealing temperature while performing
(2) After evacuating the vacuum chamber to a predetermined degree of vacuum, introducing a predetermined gas into the vacuum chamber so as to have a predetermined partial pressure;
(3) A step of sealing the display panel and the back panel via the bonding material by bringing the sealing portion into contact with the vacuum chamber filled with the gas having a predetermined partial pressure. And a method for manufacturing the image forming apparatus.

  In the present invention, the display panel and the back panel are separated from each other by a sufficient distance to obtain a sufficient conductance for gas, and the temperature is raised to the sealing temperature, so that degassing from the member can be sufficiently performed. A uniform vacuum container can be produced, and stable electron emission characteristics can be obtained by introducing gas after sufficient degassing and then bonding the gas when it has settled to a predetermined partial pressure.

  In the above invention, an airtight space is formed by joining the display panel and the back panel. Between the display panel and the back panel, there may be a frame or a spacer arranged to form an atmospheric pressure resistant structure, and the atmosphere at the time of joining is reflected in the atmosphere of the airtight space. At this time, by adjusting the atmosphere in a state where the gap between the display panel and the rear panel is larger than the gap after bonding, the adjusted atmosphere is more airtight space (portion that becomes the airtight space after bonding). This is suitable because it is easily reflected in the atmosphere.

In the present invention, the gas to be introduced is preferably a gas composed of at least one kind of gas composed of He, Ne, Ar, Kr, Xe, and H ₂ . The purpose of selecting the gas to be introduced is to reduce the gas from being positively ionized and damaging the cold cathode electron-emitting device. The selection criteria for the gas to be introduced are (1) to select a gas having a small ionization cross section in order to reduce the collision probability between electrons and gas molecules, and to reduce the gas molecule density, and (2) the first ionization voltage. It is important that the ionization is high and difficult to ionize, and that the atomic weight is small in order to reduce the degree of damage even if ionization is performed. As a result of experiments, it has been found that the gas described above is effective. However, it seems to be most important that the ionization cross-section is small, and it is necessary to make the ionization cross-section at least 10 ⁻¹⁷ cm ² or less. It turned out. When a gas having an ionization cross-sectional area of 10 ⁻¹⁶ cm ² was introduced, the damage to the cold cathode electron-emitting device was greater than that of a panel without introduction.

  According to the present invention, damage to the cold cathode electron-emitting device due to discharge or the like can be suppressed, and the inside of the vacuum envelope can be evacuated in a short time. It is possible to obtain an image forming apparatus capable of precisely controlling the relative arrangement of the emitting element and the phosphor to prevent color misregistration and the like.

The best mode for carrying out the present invention will be described.
Hereinafter, embodiments of the present invention will be specifically described. An image forming apparatus according to the present invention includes a display (front) panel having a phosphor screen, a back panel having a cold cathode electron emission element array or an MIM type cold cathode electron emission element array that emits an electron beam facing the display panel, and Are sealed with a bonding material to provide an evacuation space. In the evacuation space, at least one of He, Ne, Ar, and H ₂ gas, or this gas and Kr, Xe That gas has been introduced. The cold cathode electron-emitting device array or the MIM type cold cathode electron-emitting device array can be the same as in the prior art.

  An example of a method for manufacturing the image forming apparatus of the present invention will be described with reference to the chart of FIG. First, the production of the back panel will be described. In order to clean the soda glass substrate and prevent sodium diffusion from the glass substrate, an undercoat film composed of a silicon nitride film and a silicon oxide film is sequentially formed, and then a wiring and a cold cathode electron-emitting device are formed. (R-1). A frit glass for fixing the support frame was formed at a desired position by printing (R-2). Through the above steps, simple matrix wiring was performed on the rear panel, and a cold cathode electron-emitting device and an adhesive for the support frame were formed.

  The production of the front panel will be described. First, a phosphor and a black conductor were formed on a soda glass substrate by a printing method. A smoothing process was performed on the inner surface of the fluorescent film, and then an Al film was deposited by vacuum evaporation or the like to form a metal back (F-1). Next, using soda glass as a substrate, a frit glass for fixing the support frame was formed at a desired position by printing. Further, the spacer was bonded to the black conductor with a frit. Through the above steps, a phosphor in which the three primary color phosphors are arranged in stripes, an adhesive for a support frame, a spacer, and the like were formed on the front panel (F-2).

Next, the front panel, the back panel, and the support frame were introduced into a vacuum chamber and evacuated (FR-1). The temperature was raised with a predetermined profile while evacuating, and the temperature was raised to the sealing temperature while degassing water, oxygen, carbon monoxide, carbon dioxide and the like. The sealing temperature at this time is determined by frit glass (FR-2). After evacuating to a degree of vacuum of about 10 ⁻⁵ Pa and sealing the vacuum container, the predetermined gas from the introduction pipe is set to a partial pressure of 10 ⁻⁴ Pa in the vacuum chamber so that the predetermined gas remains inside the container. In this case, He gas was introduced. After that, while maintaining the sealing temperature, the front panel, the support frame, the spacer, and the back panel were brought into contact with each other and pressed while the cold cathode electron-emitting device and the front panel were aligned on the adjustment stage of X, Y, and θ. After maintaining the state for 10 minutes, the temperature was lowered at 3 ° C. per minute, and when the temperature was lowered by 10 ° C. from the sealing temperature, the alignment was stopped, the stage was freed, and cooled to room temperature (FR-3). After cooling to room temperature, it was taken out from the vacuum chamber and subjected to getter treatment by a high-frequency heating method in order to maintain the degree of vacuum after sealing (FR-4).

  In the image forming apparatus completed as described above, each cold cathode electron-emitting device is caused to emit electrons by being applied to the cold-cathode electron-emitting device through a signal generating means through a terminal outside the container. Was applied, the electron beam was accelerated, collided with the fluorescent film, and excited and emitted to display an image. As a result, there was no misalignment between the cold cathode electron-emitting device and the phosphor, and luminance variations and color mixing due to the misalignment were not observed.

  An example of a method and apparatus for manufacturing an image forming apparatus according to the present invention will be described. In FIG. 5, 10 is a vacuum tank, 11 is a gas introduction pipe for introducing into the vacuum tank, 12 is an exhaust pipe for evacuation, 141 is a front panel, 145 is a back panel, 22 is a support frame, 23 is 141 and 145 Is a frit glass mainly made of low-melting glass.

  In FIG. 5, the joining member 23 is formed in advance on the front panel and the back panel, but may be formed in advance on the joining surface of the support frame 22 to the front panel and the back panel. In addition, it is desirable to remove organic substances in advance from the frit glass by calcination.

  30 is a stage that is a position adjusting means for adjusting the position of the front panel in the X, Y, and θ directions, 31 is a heating plate that is a heating means for heating the front panel, and 32 is a position adjustment of the front panel in the Z direction. It also serves as a mechanism that pressurizes after bringing the front panel, the back panel, and the support frame into contact with each other. Reference numeral 33 denotes a stage as position adjusting means for adjusting the position of the rear panel in the X, Y, and θ directions, and reference numeral 34 denotes a heating plate as heating means for heating the rear panel.

  In FIG. 5, the front panel is installed above the apparatus, and the back panel is installed below the apparatus. However, the installation location is not limited to this, and it is only necessary to select which one is installed upward. Further, the stages 30 and 33 which are X, Y and θ direction position adjusting means for the front panel and the rear panel are not necessarily required for both the front panel and the rear panel. Moreover, it is preferable to have a heat insulating structure such as a heat insulating material between the heating plates 31 and 34 and the stages 30 and 33.

  The front panel 141 and the back panel 145 are respectively fixed to the heating plates 31 and 34 by a fixing jig (not shown). Frit glass is disposed in advance at locations where the support frame 22 is bonded to the back panel 145 and the front panel 141.

In addition, when constructing a large display panel, an atmospheric pressure resistant structure called a spacer is previously bonded to the front panel side or the back panel side. At the same time, the support frame is bonded to the front panel side or the back panel side. You can leave it. In this manner, the front panel and the rear panel are fixed to the heating plates 31 and 34, respectively, and vacuum exhaust is performed from the exhaust port 12 while raising the temperature to the vicinity of the softening point of the glass frit at a distance that can secure a sufficient conductance for gas. After sufficiently evacuating and confirming with a chamber atmosphere measuring device that water, carbon dioxide, etc. generated from the degassing of the member and glass frit has become below a desired value, the He is introduced into the He from the gas introduction pipe 11. After the gas is introduced and the He gas partial pressure in the chamber has been stabilized to about 10 ⁻⁴ Pa, the front panel X, Y, θ direction adjustment stage is maintained so that the front panel and the rear panel maintain a predetermined positional relationship. 30 or the X, Y, θ direction adjustment stage 33 of the rear panel, or the front panel and the rear surface using the Z direction adjustment mechanism of the front panel while adjusting the relative positional relationship between the front panel and the rear panel using the direction. The panel and the support frame are brought into contact and pressure is applied. After maintaining the temperature while applying pressure for a certain period of time and adjusting the relative positions of the front panel and the rear panel, the temperature is lowered with a predetermined temperature profile, and the glass frit is cured and pasted. The relative position between the front panel and the rear panel is adjusted from the softening point of the glass frit to a desired temperature until the frit starts to harden and maintains a certain degree of fluidity. Further, after the glass frit is completely cured by lowering the temperature, the glass frit is gradually cooled to about room temperature and taken out from the vacuum chamber.

Example 1 will be described. In the first embodiment of the present invention, it will be explained that damage to the cold cathode electron-emitting device can be suppressed by introducing the gas of the present invention into the sealed container of the panel. The MIM type FED type 5 panel shown in FIG. 3 and FIG. 4 was prepared, and the introduced gas was changed, and the evaluation index was as follows: (time when anode current was reduced by 10% / time when anode current was reduced by 10% in the reference panel) The effect of the introduced gas was evaluated with a magnification of In this embodiment, the panel manufacturing process is a process in which a front panel and a rear panel are arranged in a vacuum chamber, gas is introduced after evacuation, and sealing is performed thereafter. The reference panel is an MIM type panel having a vacuum degree of 1 × 10 ⁻⁴ Pa, an anode voltage of 5 kV, and a support frame height of 3 mm in the sealed space without introducing gas. The gas introduction panel is an MIM type panel comprising a vacuum chamber after exhausting to 1 × 1 ⁻⁶ Pa and introducing gas, and a vacuum degree of 1 × 10 ⁻⁴ Pa, an anode voltage of 5 kV, and a support frame height of 3 mm in the sealed space. is there.

FIG. 6 shows the evaluation results of the panels produced with each introduced gas. The evaluation index is (the time when the anode current is reduced by 10% / the time when the anode current is reduced by 10% on the reference panel), which corresponds to the lifetime improvement magnification of the cold cathode electron-emitting device. It can be seen that the life can be improved by using at least one of He, Ne, Ar, and H ₂ as the introduction gas. The introduction of Xe gas alone deteriorated the lifetime, but this is thought to be because the atomic weight was 131.293 and the mass was so large that damage to the MIM element was large. Although good values were not obtained with Kr gas alone, good characteristics were obtained when Kr and Xe were used together with He gas or the like. As a comparative example, the case of N ₂ gas and O ₂ gas was also shown, but almost no gas introduction effect was observed, and since it is a reactive gas, it is considered to have an adverse effect in the long term. Table 1 shows the atomic weight, first ionization potential, and ionization cross section of various gases. It is considered that an effective gas needs to have a small ionization cross section and a small atomic weight. Ionization cross section data are values obtained from the Atomic Molecular Numerical Database website of the National Institute for Fusion Science.

A second embodiment will be described. In the second embodiment of the present invention, the cold cathode electron-emitting device is a panel using a field emission device (FE type FED) which is a kind of cold cathode electron-emitting device. It will be described that the damage to the cold cathode electron-emitting device can be suppressed by performing the process inside. FIG. 8 shows a schematic cross-sectional view of the FE type FED. 131 is a back panel, 132 is a front panel, 133 is a cathode, 134 is a gate electrode, 135 is an insulating film between the gate and the cathode, 138 is an insulating layer between the gate and the focusing electrode, and 136 is a focusing electrode. FE-type FED type 5 panel was prepared, introduced gas was changed, and introduced as an evaluation index with a magnification of (time when anode current was reduced by 10% / time when anode current was reduced by 10% with reference panel) The effect of gas was evaluated. The panel manufacturing process is a process of the present invention in which a front panel and a rear panel are arranged in a vacuum chamber, gas is introduced after evacuation, and sealing is performed thereafter. The reference panel condition is an FE type panel having a degree of vacuum of 1 × 10 ⁻⁴ Pa, an anode voltage of 5 kV, and a support frame height of 3 mm in the sealed space without introducing gas. The gas introduction panel is an FE type panel comprising a vacuum chamber of 1 × 1 ⁻⁶ Pa after introducing a gas and a vacuum degree of 1 × 10 ⁻⁴ Pa, an anode voltage of 5 kV, and a support frame height of 3 mm in the sealed space. is there.

FIG. 9 shows the evaluation results of the panels produced with each introduced gas. The evaluation index is (the time when the anode current is reduced by 10% / the time when the anode current is reduced by 10% on the reference panel), which corresponds to the lifetime improvement magnification of the cold cathode electron-emitting device. It can be seen that the life can be improved by using at least one kind of gas composed of He, Ne, and Ar as the introduction gas. The introduction of Xe gas alone deteriorated the lifetime, but this is considered to be because the atomic weight was 131.293 and the mass was so large that the damage to the FE type element was great. Although good values were not obtained with Kr gas alone, good characteristics were obtained when Kr and Xe were used together with He gas or the like. As a comparative example, the case of N ₂ gas and O ₂ gas was also shown, but almost no gas introduction effect was observed, and since it is a reactive gas, it is considered to have an adverse effect in the long term.

A third embodiment will be described. In the MIM type FED shown in Example 1, the partial pressure of the introduced gas is changed to indicate that the introduced gas partial pressure has an effective range. The panel is manufactured according to the present invention in a process of performing evacuation while heating the panel in the vacuum chamber in which the panel is introduced, introducing gas up to a predetermined partial pressure in the vacuum chamber, and then performing sealing. It was. In FIG. 10, the horizontal axis represents the introduced gas partial pressure (Pa). A partial pressure of less than 10 ⁻¹¹ Pa is not practical because it takes a long time to evacuate the sealed space of the panel. A partial pressure higher than 10 ⁻² Pa is not preferable because the inflow of electrons to the anode is reduced and the brightness of the panel is lowered, and damage to the cold cathode electron-emitting device is increased by discharge or the like. Therefore, the introduced gas partial pressure is preferably 10 ⁻¹¹ Pa or more and 10 ⁻² Pa or less. More preferably, it is 10 ⁻⁸ Pa or more and 10 ⁻⁴ Pa or less.

  Example 4 will be described. An example of a method for manufacturing the image forming apparatus of the present invention will be described with reference to the chart of FIG. The production of the back panel will be described. First, a 2 mm thick soda lime glass substrate is washed, and an undercoat film made of a two-layer film having a silicon nitride film thickness of 100 nm and a silicon oxide film thickness of 100 nm is formed by sputtering in order to prevent sodium diffusion from the glass substrate. Were sequentially formed, and then a wiring and a MIM type FED were formed (R-1). Next, a frit glass for fixing the support frame was formed at a desired position by printing (R-2). Through the above steps, the MIM type FED array and the support frame adhesive were formed by simple matrix wiring on the back panel.

  The production of the front panel will be described. An RGB pattern of P22 phosphor and a black conductor were formed on a soda lime glass substrate by a printing method. A smoothing process was performed on the inner surface of the fluorescent film, and then an Al film having a thickness of 75 nm was deposited using vacuum evaporation or the like to form a metal back. The purpose of providing the metal back is to improve the light utilization rate by specularly reflecting a part of the light emitted from the fluorescent film, to protect the fluorescent film from the collision of negative ions, and to apply the electron beam acceleration voltage. For example, to act as a conductive path for excited electrons, and so on. The metal back was formed by forming a fluorescent film on a soda lime glass substrate, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon (F-1). Next, frit glass for fixing the support frame was formed at a desired position by printing using soda lime glass as a substrate. Further, a spacer having a thickness of 3 mm was adhered to a black conductor with a frit. Through the above steps, a phosphor in which the three primary color phosphors are arranged in stripes, an adhesive for a support frame, a spacer, and the like were formed on the front panel (F-2).

Next, the front panel, the back panel, and the support frame were introduced into a vacuum chamber and evacuated (FR-1). The temperature was raised with a predetermined profile while evacuating, and the temperature was raised to the sealing temperature while degassing water, oxygen, carbon monoxide, carbon dioxide and the like. The sealing temperature at this time is determined by the frit glass. In this case, it was set to 430 ° C. (FR-2). The partial pressure of the predetermined gas is set to 10 ⁻⁴ Pa from the introduction pipe in the vacuum chamber so that the predetermined gas remains in the container after the vacuum container is sealed after the vacuum is exhausted to about 10 ⁻⁵ Pa. In this case, He gas was introduced. After that, while maintaining the sealing temperature, the front panel, support frame, spacer, and back panel are brought into contact with the MIM type FED array and the front panel while being adjusted on the X, Y, and θ adjustment stages, and pressurized. Was held for 10 minutes, and then the temperature was lowered at 3 ° C. per minute. When the temperature was lowered by 20 ° C. from the sealing temperature, the alignment was stopped, the adjustment stage was made free and cooled to room temperature (FR-3). After cooling to room temperature, it was taken out from the vacuum chamber and subjected to getter treatment by a high-frequency heating method in order to maintain the degree of vacuum after sealing (FR-4). In the image display apparatus shown in FIG. 7 according to the manufacturing method of the present invention completed as described above, the signal is applied to each MIM type FED array from the signal generating means (not shown) through the container external terminal. Thus, electrons were emitted, a high voltage of 3 kV was applied to the metal back through the high voltage terminal, the electron beam was accelerated, collided with the fluorescent film, and excited and emitted to display an image. As a result, there was no positional deviation between each MIM type FED array and the phosphor, and luminance variations and color mixing due to the positional deviation were not observed.

  Example 5 will be described. One embodiment of the production method of the present invention is shown in FIG. In FIG. 5, 10 is a vacuum tank, 11 is a gas introduction pipe for introducing into the vacuum tank, 12 is an exhaust pipe for evacuation, 141 is a front panel, 145 is a back panel, 22 is a support frame, 23 is 141 and 145 Is a frit glass mainly made of low-melting glass.

  In FIG. 5, the joining member 23 is formed in advance on the front panel and the back panel, but may be formed in advance on the joining surface of the support frame 22 to the front panel and the back panel. In addition, it is desirable to remove organic substances in advance from the frit glass by calcination.

  30 is a stage that is a position adjusting means for adjusting the position of the front panel in the X, Y, and θ directions, 31 is a heating plate that is a heating means for heating the front panel, and 32 is a position adjustment of the front panel in the Z direction. It also serves as a mechanism that pressurizes after bringing the front panel, the back panel, and the support frame into contact with each other. Reference numeral 33 denotes a stage as position adjusting means for adjusting the position of the rear panel in the X, Y, and θ directions, and reference numeral 34 denotes a heating plate as heating means for heating the rear panel.

  In FIG. 5, the front panel is installed above the apparatus and the back panel is installed below the apparatus. However, the installation location is not limited to this, and it is only necessary to select which one is installed upward. Further, the stages 30 and 33 which are X, Y and θ direction position adjusting means for the front panel and the rear panel are not necessarily required for both the front panel and the rear panel. Moreover, it is preferable to have a heat insulating structure such as a heat insulating material between the heating plate 31 and the stage 30 and between the heating plate 34 and the stage 33.

  The front panel 141 and the back panel 145 are respectively fixed to the heating plates 31 and 34 by a fixing jig (not shown). Frit glass is disposed in advance at the bonding position of the support frame 22 to the back panel 145 and the front panel 141.

In addition, when constructing a large display panel, an atmospheric pressure resistant structure called a spacer is previously bonded to the front panel side or the back panel side. At the same time, the support frame is bonded to the front panel side or the back panel side. You can leave it. In this manner, the front panel and the rear panel are fixed to the heating plates 31 and 34, respectively, and vacuum exhaust is performed from the exhaust port 12 while raising the temperature to the vicinity of the softening point of the glass frit at a distance that can secure a sufficient conductance for gas. After sufficiently evacuating and confirming with a chamber atmosphere measuring device that water, carbon dioxide, etc. generated from the degassing of the member and glass frit has become below a desired value, the He is introduced into the He from the gas introduction pipe 11. After introducing the gas and confirming that the He gas partial pressure in the chamber has stabilized at about 10 ⁻⁴ Pa, adjust the X, Y, and θ directions of the front panel so that the front panel and the rear panel maintain a predetermined positional relationship. While adjusting the relative positional relationship between the front panel and the rear panel using the stage 30, or the X, Y, θ direction adjustment stage 33 of the rear panel or its direction, the front panel is adjusted using the Z direction adjustment mechanism of the front panel. The back panel and the support frame are brought into contact with each other and pressure is applied. After maintaining the temperature while applying pressure for a certain period of time and adjusting the relative positions of the front panel and the rear panel, the temperature is lowered with a predetermined temperature profile, and the glass frit is cured and pasted. The relative positions of the front panel and the rear panel are adjusted until the glass frit softens from the softening point to a desired temperature and maintains a certain fluidity while the frit starts to harden. Further, after the glass frit is completely cured by lowering the temperature, the glass frit is gradually cooled to about room temperature and taken out from the vacuum chamber. FIG. 7 shows an outline of an example of the completed image forming apparatus. The front panel 141 and the back panel 145 are held by a support frame 143 and a spacer 147, and have an atmospheric pressure resistant structure.

  As described above, in the example of the manufacturing method, panel baking, evacuation, gas introduction, sealing, and the like have been performed in the same vacuum chamber, but the present invention is limited to being performed in the same vacuum chamber. Instead, each step may be performed in separate vacuum chambers, and several steps may be performed in the same vacuum chamber. In addition, each step may be set on one line or may be set on a star arrangement.

  In this embodiment, the cold cathode electron-emitting devices are described using the MIM type and the FE type. However, the present invention is not limited to these, and the present invention is not limited to the SC type, the FE type using a narvon nanotube, It is also effective in an image forming apparatus and a manufacturing method using a ballistic electron surface emission electron source, a high-efficiency cold cathode electron-emitting device, and the like.

  As described above, according to the image forming apparatus and the manufacturing method of the present invention, in the display using the cold cathode electron-emitting device, the cold cathode electron-emitting device is damaged by discharge, positive ions, etc., which have been the conventional problems. As a result, it is possible to suppress fluctuations in luminance and deterioration in luminance due to reduction of electron emission caused by, which is highly beneficial to the industry. Also in the manufacturing method, the back panel and the front panel are separated from each other by a sufficient distance to obtain a sufficient conductance for the gas, the temperature is raised to the sealing temperature, and the desired gas is introduced after sufficiently degassing the member. Thus, stable electron emission characteristics can be obtained. Further, in order to form a vacuum envelope by adhering the electron source and the image forming member in a predetermined positional relationship in the vicinity of the sealing temperature, a relative position shift due to thermal expansion and softening of the frit glass is corrected. In addition, the electron source substrate and the front panel can be bonded with high positional accuracy, and a high-quality image forming apparatus free from luminance unevenness and color mixture due to positional deviation can be manufactured.

Explanatory drawing of an example of the manufacturing process of the image forming apparatus of this invention. Explanatory drawing of the structure of a MIM type cathode. Explanatory drawing which shows the production process of a MIM type cathode array. Explanatory drawing which shows the production process of a MIM type cathode array. FIG. 10 is an explanatory diagram illustrating an example of a method for manufacturing an image forming apparatus according to a fifth embodiment. FIG. 3 is a chart for explaining the evaluation results of Example 1. FIG. FIG. 10 is a schematic explanatory diagram of an image forming apparatus according to a fifth embodiment. Explanatory drawing of the cross section of FE type FED of Example 2. FIG. The chart explaining the evaluation result of Example 2. FIG. Explanatory drawing of the range of the introduction gas partial pressure of Example 3. FIG.

Explanation of symbols

1 ... soda glass substrate 2 ... SiN _x undercoat film 3 ... SiO ₂ undercoat film 4 ... field insulating film 5 ... contact electrode 6 ... bus electrode 7 ... protective insulating film 8 ... upper electrode 9 ............ Lower electrode 10 ... Vacuum tank 11 ... Gas introduction pipe introduced into vacuum tank 12 ... Vacuum exhaust pipe 14 ... Tunnel insulation film 15 ... Resist 22 ... Support frame 23 ... Joint 30... Stage for adjusting position in X, Y, θ direction 31... Heating plate 32 .. Z position adjusting means 33... To adjust position in X, Y, and θ directions The stage is a position adjustment means 34... Heating plate 131... Rear panel 132... Front panel 133 ... Cathode 134 ... Gate electrode 135 ... Insulating film 136 between the gate and cathode 136 Focusing electrode 13 Insulating film 141 between ‥‥ gate and the focusing electrodes ‥‥ front panel 143 ‥‥ support frame 145 ‥‥ rear panel 147 ‥‥ spacer

Claims (8)

Forming an image by providing a vacuum exhaust space by sealing a display panel having a phosphor screen and a back panel having a cold cathode electron-emitting device array that emits an electron beam facing the display panel with a bonding material Device,
An image forming apparatus, wherein a gas composed of at least one of He, Ne, and Ar or any one of Kr and Xe is introduced into the evacuation space. 2. The image formation according to claim 1, wherein a partial pressure in the vacuum exhaust space of the gas composed of at least one of the He, Ne, and Ar, or the gas and any one of the gases Kr and Xe is 10 ⁻² Pa or less. apparatus. 2. The image formation according to claim 1, wherein a partial pressure in the vacuum exhaust space of the gas composed of at least one of the He, Ne, and Ar, or the gas and any one of the gases Kr and Xe is 10 ⁻¹¹ Pa or more. apparatus. A display panel having a phosphor screen and a rear panel having an MIM-type cold cathode electron-emitting device array that emits an electron beam opposite to the display panel are sealed with a bonding material to provide a vacuum exhaust space. An image forming apparatus,
Wherein the evacuation space, He, Ne, Ar, gas consisting of at least one kind of H _2, or the gas and Kr, the image forming apparatus characterized by either gas Xe was introduced. The partial pressure in the vacuum exhaust space of the gas composed of at least one kind of the gas composed of He, Ne, Ar, and H ₂ or the gas and any one of Kr and Xe is 10 ⁻² Pa or less. 5. The image forming apparatus according to 4. It said He, Ne, Ar, claim gas consisting of at least one kind of gas comprising _{H 2,} or the gas and Kr, the partial pressure in the evacuated space of any of the gases Xe ^{is 10 -11} Pa or more 5. The image forming apparatus according to 4. Forming an image by providing a vacuum exhaust space by sealing a display panel having a phosphor screen and a back panel having a cold cathode electron-emitting device array that emits an electron beam facing the display panel with a bonding material A device manufacturing method comprising:
In the vacuum chamber, the display panel and the back panel are held between the first heating unit and the second heating unit in a state where the sealing portion is not in contact with the vacuum chamber while evacuating the vacuum chamber. A heating step of heating the display panel, the back panel and the bonding material to a sealing temperature, and a gas comprising at least one of He, Ne, and Ar after evacuating the vacuum chamber to a predetermined vacuum level Or a step of introducing the gas and any one of Kr and Xe into the vacuum chamber so as to have a predetermined partial pressure, and a state in which the vacuum chamber is filled with the gas having a predetermined partial pressure. And a step of sealing the display panel and the back panel through the bonding material by bringing the sealing portion into contact therewith. A display panel having a phosphor screen and a rear panel having an MIM-type cold cathode electron-emitting device array that emits an electron beam opposite to the display panel are sealed with a bonding material to provide a vacuum exhaust space. An image forming apparatus manufacturing method comprising:
In the vacuum chamber, the display panel and the back panel are held between the first heating unit and the second heating unit in a state where the sealing portion is not in contact with the vacuum chamber while evacuating the vacuum chamber. A heating step of heating the display panel, the back panel, and the bonding material to a sealing temperature; and evacuating the vacuum chamber to a predetermined degree of vacuum, and then at least one of He, Ne, Ar, and H ₂ Or a step of introducing the gas and any one of Kr and Xe into the vacuum chamber so as to have a predetermined partial pressure, and the vacuum chamber is filled with the gas having a predetermined partial pressure. And a step of sealing the display panel and the back panel through the bonding material by bringing the sealing portion into contact therewith.

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