Abstract:
An electron device such as a fluorescent display tube is provided, wherein a simple ring-less getter can be simply fixed and arranged with a large degree of freedom. The ring-less getter is securely fixed to the inner surface of the glass anode substrate using laser beams. The laser beam is irradiated onto the ring-less getter from outside the anode substrate. Thus, the laser beam passes through the anode substrate thus heating and melting the ring-less getter. The corresponding inner surface of the anode substrate is melted through the heating. In cooling, the portion where the ring-less getter and the anode substrate are in a molten state is solidified, so that the ring-less getter is bonded to the anode substrate. The ring-less getter is shaped arbitrarily through press-working a getter material.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to International Patent Application PCT/JP03/05772, filed 08 May 2003, which claims priority of JP application 2002-136338 filed 10 May 2002. 
     TECHNICAL FIELD 
     The present invention relates to electron devices with ring-less getters, suitable in use for electron tubes (such as fluorescent display tubes, CRTs, Plasma Display Panels (PDPs), and the like) and electroluminescent displays (ELDs). Moreover, the present invention relates to a method for fixing a ring-less getter and a method for activating the same. 
     BACKGROUND 
     In electron devices, such as electron tubes and ELDs, the hermetic container contains a getter. The getter is heated and activated by illuminating radio waves or laser beams from the outside. Thus, the getter adsorbs gases or moisture within the envelope or emits specific gases. For example, when the electron tube belongs to a vacuum tube, the getter adsorbs gases existing in the envelope, thus increasing the degree of vacuum. When the electron tube belongs to a discharge tube, the getter adsorbs unnecessary gas or harmful gas, other than a discharging gas having xenon or neon as a principal constituent, introduced in the envelope. In the case of ELDs, the getter adsorbs moisture within the hermetic container to prolong the serviceable life. 
     A fluorescent display tube, in which a conventional getter is mounted, will be explained below by referring to  FIGS. 7 and 8 . In  FIGS. 7 and 8 , like numerals are attached to the common constituent elements. 
       FIG. 7  is a cross-sectional view illustrating a fluorescent display tube in which a conventional ring getter is mounted. 
       FIG. 7(   a ) is a cross-sectional view illustrating the portion taken along the line Y 2 -Y 2  in  FIG. 7(   b ).  FIG. 7(   b ) is a cross-sectional view illustrating the portion taken along the line Y 1 -Y 1  in  FIG. 7  ( a ) . Anode electrodes  55 , each on which a fluorescent substance is coated, are formed on a glass substrate  511 . The mounting member  52  of the holder member (anchor or support)  531  for cathode filaments  532  is formed on a glass substrate  511 . A ring container  541 , which is filled with a getter material  542 , is welded to the getter holder member  543 . Grids  56  are disposed between each anode electrode  55  and the filaments  532 . Numeral  512  represents a glass front substrate. Each of numerals  513  to  515  represents a glass side plate. Anode wiring conductors, Nesa films on the front substrate, and others are omitted here. 
     The ring container  541 , being an nickel-plated iron envelope, is filled with a getter material  542 , made of a mixture of Ba, Ma, or an alloy of them and an additive metal (such as Al or Ni). 
     In order to activate the ring getter  54 , the ring container  541  is heated through the high-frequency induction heating from outside the fluorescent display tube to flush (evaporating) the getter material  542 . The particles of the evaporated getter material  542  make a getter mirror film over an inner surface of the front substrate  543 . 
     The ring getter  54 , having a special ring container  541  and a special holder member  543 , is difficult to be miniaturized and requires a large mounting space. The ring getter container  541  has to be spaced at least 1 mm from the anode substrate  511  because the anode substrate  511  may be cracked during heating. This makes it difficult to miniaturize and thin the fluorescent display tube. Moreover, both the ring container  541  and the holder member  543  lead to higher machining costs. The difficult work for mounting them increases the fabrication cost of the fluorescent display tube. 
     The mounting place of the ring getter  54  is limited to the metal component such as the mounting member  52 . Hence, there is no degree of freedom in the arrangement of the ring getter  54 . 
     In order to improve the drawback of the ring getter shown in  FIG. 7 , the ring getter shown in  FIG. 8 , which does not use the special ring container or the special holder member, has been proposed. 
     Referring to  FIG. 8(   a ), a ring-less getter  54  is formed of an pocket (or a recess), which is filled with a getter material, in the inner surface of the front substrate  512  (refer to Japanese Patent Laid-open Publication No. Tokkai-Hei 5-114373). In this example, the pocket formed in the front substrate  512  leads to the high machining cost. However, the ring-less getter is filled with a necessary amount of getter material enough to provide a getter effect because a deep pocket cannot be made sufficiently. 
     Referring to  FIG. 8(   b ), using the screen printing or vacuum deposition, the film ring-less getter  54 , made of a thick or thick film getter material, is formed in the inner surface of the front substrate  512  (refer to Patent Publication No. WO93/16484). In this example, the thick or thin ring-less getter  54  cannot hold a necessary amount of getter material to provide a sufficient getter effect. 
     The ring-less getter  54  of  FIG. 8(   c ) may be considered in place of the ring-less getter of  FIGS. 8(   a ) and  8 ( b ). In the ring-less getter  54  shown in  FIG. 8(   c ), the getter material is sintered in the form of a disc of a diameter of 2 mm and a thickness of 0.5 mm. The ring-less getter  54  is attached to the inner surface of the front substrate  512  with the fritted glass  57 . In this example, the ring-less getter  54  having a large thickness can hold a sufficient amount of getter material. However, because the adhesive strength, particularly, the adhesive strength between the ring-less getter and the fritted glass, is not strong (the shear strength is less than 1 N), the ring-less getter  54  may be dropped down during the fabrication process of the fluorescent display tube. 
     Because the getter material deteriorates at high sintering temperatures (for example, BaAl4 is oxidized), the fritted glass for adhesion is sintered at a low sintering temperature (for example, less than 450° C.) in the atmosphere. However, the low sintering temperature causes the residue of an organic constituent (for example, ethyl cellulose) in the fritted glass paste, thus resulting in deterioration of the reliability of the fluorescent display tube. Moreover, in order to flush the ring-less getter  54  with the laser beam, the laser beam reaching the fritted glass  57  releases a large amount of gases, so that the emission of the filament  532  is degraded remarkably. 
     The present invention is made to solve the above-mentioned problems in the conventional ring getters and the conventional ring-less getters. 
     An object of the invention is to provide an electron device with a ring-less getter. The ring-less getter has a simple configuration and a degree of freedom in arrangement. Moreover, the ring-less getter is easily mountable and is suitable for miniaturization and thinning of electron devices, such as electron tubes or ELDs. Moreover, the ring-less getter does not cause cracking of a glass substrate due to heating during mounting or during flushing and does not generate gases deteriorating the function of an electron tube. 
     Moreover, another object of the invention is to provide a method for fixing a ring-getter and a method for activating the same. 
     SUMMARY 
     In an aspect of the present invention, an electron device comprises a glass substrate disposed in a hermetic container, and a ring-less getter bonded onto the glass substrate, with an optical energy. 
     In another aspect of the present invention, an electron device comprises a glass substrate disposed in a hermetic container, a ring-less getter bonded onto the glass substrate, with an optical energy, and a getter mirror film formed by activating the ring-less getter bonded with an optical energy. 
     In the electron device, the optical energy is a laser beam. 
     In the electron device, the glass substrate builds part of the hermetic container. 
     In the electron device, the ring-less getter is made through press-working a getter material powder. 
     In another aspect of the present invention, an electron device comprises a resin hermetic container, and a ring-less getter bonded onto an inner surface of the resin hermetic container, with an optical energy. 
     In further another aspect of the present invention, a method for fixing a ring-less getter, comprises the steps of disposing a ring-less getter on a glass substrate in an electron device, irradiating an optical energy onto the ring-less getter from a surface of the glass substrate, opposite to a surface of the glass substrate on which the ring-less getter is disposed, and bonding the ring-less getter on the glass substrate. 
     In the method, the optical energy is a laser beam. In still another aspect of the invention, a method for activating a ring-less getter, comprises the steps of disposing a ring-less getter on a glass substrate in an electron device, irradiating an optical energy onto the ring-less getter from a surface of the glass substrate, opposite to a surface of the glass substrate on which the ring-less getter is disposed, bonding the ring-less getter on the glass substrate, and irradiating an optical energy the ring-less getter to activate the ring-less getter. 
     In the method, the optical energy is a laser beam. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This and other objects, features, and advantages of the present invention will become more apparent upon a reading of the following detailed description and drawings, in which: 
         FIGS. 1(   a ) and  1 ( b ) are cross-sectional views, each illustrating a fluorescent display tube according to a first embodiment of the present invention; 
         FIGS. 2(   a ) and  2 ( b ) are cross-sectional views, each illustrating a fluorescent display tube according to a second embodiment of the present invention; 
         FIG. 3  is a cross-sectional view illustrating a fluorescent display tube according to a third embodiment of the present invention; 
         FIG. 4  is a cross-sectional view illustrating a fluorescent display tube according to a fourth embodiment of the present invention; 
         FIGS. 5(   a ),  5 ( c ),  5 ( d ), and  5 ( e ) are plan views, each illustrating a ring-less getter according to an embodiment of the present invention and  FIGS. 5(   b ) and  5 ( f ) are cross-sectional views, each illustrating a ring-less getter according to an embodiment of the present invention; 
         FIGS. 6(   a ),  6 ( b ) and  6 ( c ) are diagrams, each explaining a method for fixing a ring-less getter according to an embodiment of the present invention and a method for flushing the same; 
         FIGS. 7(   a ) and  7 ( b ), are cross-sectional views, each illustrating a fluorescent display tube with a conventional ring getter therein; and 
         FIGS. 8(   a ),  8 ( b ) and  8 ( c ) are cross-sectional views, each illustrating a fluorescent display tube with a conventional ring-less getter therein. 
     
    
    
     DETAILED DESCRIPTION 
     A fluorescent display tube (being one of electron devices), a ring-less getter fixing method, and a ring-less getter activating method, according to an embodiment of the present invention, will be described below by referring to  FIGS. 1 to 6 . Like numerals are attached to the same constituent elements. 
       FIG. 1  is a cross-sectional view illustrating a fluorescent display tube according to a first embodiment of the present invention.  FIG. 1(   a ) is a cross-sectional view illustrating a portion taken along the line X 2 -X 2  in the arrow direction, shown in  FIG. 1(   b ).  FIG. 1(   b ) is a cross-sectional view illustrating a portion taken along the line X 1 -X 1  in the arrow direction, shown in  FIG. 1(   a ). 
     Referring to  FIG. 1(   a ), numeral  111  represents a glass substrate,  112  represents a glass front substrate, and  113  to  115  represent a glass side plate, and  12  represents a mounting member of a filament holder member (anchor or support) formed of a metal plate. Numeral  131  represents a filament holder member formed of a metal member such as 426 alloy (Ni of 45%, Cr of 6%, Fe (remainder)). Numeral  132  represents a cathode filament, which is formed of W or Re—W core on which an electron emissive material such as ternary carbonate is coated. Numeral  15  represents an anode electrode formed of a metal film such as aluminum on which a fluorescent substance such as ZnO:Zn is coated. Numeral  16  represents a grid, which is formed of a stainless steel or 426 alloy disposed between the filament  132  and the anode electrode  15 . Each of numerals G 11  to G 13  represents a ring-less getter. 
     The ring-less getter, G 11  to G 13 , is made through press molding a mixed powder of powder such as BaAl4 and MgAl, or a mixed powder of BaAl 4  and MgAl and an additive metal (such as Ni, Ti, or Fe). 
     An envelope, or a hermetic container, of a fluorescent display tube is built with the anode substrate  111 , the front substrate  112  and the side plates  113  to  115 . When the side plates are integrally made in a box-like form with the anode substrate  111  or the front substrate  112 , the side plates can be omitted. 
     The ring-less getters G 11  to G 13  are bonded directly to the inner surface of the anode substrate  111  by means of the laser beam illuminated from outside the anode substrate, without using adhesive means such as an adhesive agent, (as described later) . When the ring-less getters G 11  to G 13  are selected in size, a single ring-less getter or plural ring-less getters may be used. The number of ring-less getters G 11  to G 13  depends on the total amount of the getter material needed for adsorbing gases generated in the fluorescent display tube and hence is selected according to the amount of gas. 
     The ring-less getter, G 11  to G 13 , can be press molded in a given shape. By preparing plural ring-less getters corresponding to the form of the dead space of the anode substrate  111 , the dead space can be effectively utilized as a ring-less getter fixing place. 
       FIG. 2(   a ) shows an example where the ring-less getter G 14 , G 15  is fixed on the surface of the front substrate  112 .  FIG. 2(   b ) shows an example where the ring-less getter G 16  is fixed on the surface of the side plate  114 . The arrangement of  FIG. 2(   a ) and the arrangement of  FIG. 2(   b ) may be combined together. That is, in a single fluorescent display tube, the ring-less getter G 14 , G 15  can be fixed on the inner surface of the front substrate  112  and the ring-less getter G 16  can be fixed on the side plate  114 . 
       FIG. 3  is a cross-sectional view illustrating a fluorescent display tube according to the third embodiment of the present invention. 
     Referring to  FIG. 3 , each filament  132  is suspended above the front substrate  112  and the ring-less getter G 17  is attached to the glass intermediate substrate  116 . 
     The intermediate substrate  116 , acting as a member for holding the grid  16 , has openings  117  through which electrons emitted from the filament  132  can pass to the anode electrode  15 . The intermediate substrate  116  may be used as an intermediate partition member in the envelope (or a hermetic container) of a fluorescent display tube. 
     The ends of each filament  132  are ultrasonically bonded to the metal layer (film), e.g., aluminum, acting as an anode mounting electrode formed on the front substrate  112 . That is, each end of the filament  132  is sandwiched between the metal layer  133  and the metal piece  134  and the metal piece  134  is bonded to the metal layer  133  through the ultrasonic welding (including diffusion welding, friction welding, or solid phase junction). The spacer  135 , such as an aluminum thin wire or a glass fiber, maintains the filament  132  in a predetermined height. 
     The ring-less getter G 17  in  FIG. 3  is bonded to one surface of the intermediate substrate  116  but may be bonded on both surfaces thereof. In such case, the ring-less getters are disposed on both surfaces in such a way that they are not overlapped. 
       FIG. 4  is a cross-sectional view illustrating a fluorescent display tube according to the fourth embodiment of the present invention. Referring to  FIG. 4 , the ring-less getter G 18  is bonded directly to the anode wiring conductor  151  (formed of a metal film such as aluminum) formed over the anode substrate  111 , without intervening an insulating layer of SiO2 or SiN. Here, the anode wiring conductor means a conductor connected to an anode electrode and acting as a power supply point externally derived from the fluorescent display tube. (This is applicable to the cathode wiring conductor and the grid wiring conductor.) In this case, even if the anode wiring conductor  151  is fused during the bonding of the ring-less getter G 18 , the anode wiring conductor  151  does not disconnect at the ring-less getter G 18  because the ring-less getter G 18  is metal. The ring-less getter G 18  flushes with the laser beam irradiated after the sealing of the fluorescent display tube (as described later). However, since the flushing does not cause the evaporation of all the ring-less getter G 18 , the anode wiring conductor  151  does not break down. 
     In the present embodiment, bonding the ring-less getter on the anode wiring conductor can make larger the degree of freedom in arrangement of a ring-less getter. 
     Similarly, that feature is applicable the case where the cathode wiring conductor, connected to the cathode electrode, formed on the cathode substrate (the front substrate) or the grid wiring conductor connected to the grid. 
       FIG. 5  is a plan view or a cross-sectional view illustrating a ring-less getter according to an embodiment of the present invention. 
     Each of  FIGS. 5(   a ) and  5 ( b ) shows the ring-less getter G 21  press-molded in a rectangular shape.  FIG. 5(   b ) is a cross-sectional view illustrating the portion taken along the line of X 3 -X 3   FIG. 5(   a ). 
       FIG. 5(   c ) shows the ring-less getter G 22  press-molded in a disc shape.  FIG. 5(d)  shows the ring-less getter G 23  press-molded in a doughnut shape. 
     Each of  FIGS. 5(   e ) and  5 ( f ) shows the ring-less getter G 24  press-molded in a rectangular shape.  FIG. 5(   f ) is a cross-sectional view illustrating the portion taken along the line X 4 -X 4  of  FIG. 5(   e ). The ring-less getter  24  is made of a getter material layer G 241  and a metal layer G 242 , which is formed of a metal plate or a metal material layer such as aluminum. The ring-less getter is formed by integrally press-molding the getter material and the metal plate. The ring-less getter  24  is bonded with the meal layer G 242  fixed to the fixing surface of the anode substrate. Indium, tin or its alloy,  426  alloy, aluminum, or the like may be used for the metal layer G 242 . 
     Compared with the case where only the getter material layer G 241  is used, the ring-less getter  24  with the metal layer G 242  is hard to be brittle and facilitates the work of bonding the ring-less getter G 24 . 
     The ring-less getter in  FIG. 5  has an exemplary shape but may be formed in another shape. Plural ring-less getters, corresponding to the form of the getter mounting place, may be mounted in the fluorescent display tube. Thus, the dead spaces in the fluorescent display tube can be effectively utilized. 
       FIG. 6  is a diagram explaining a ring-less getter fixing method and a ring-less getter flush activating method, each according to an embodiment of the present invention. 
     As shown in  FIG. 6(   a ), a laser beam L 1  is irradiated onto the ring-less getter G 11  disposed on the inner surface of the anode substrate  111  from outside the anode substrate  111 . There are a method of temporarily mounting a ring-less getter G 11  with a low-temperature degradable adhesive agent such as acrylic and a method of mechanically cramping a ring-less getter and then pressing it to the anode substrate. The laser beam L 1  impinges on the ring-less getter G 11  through the anode substrate  111 , without substantial absorption. The ring-less getter G 1  is heated and fused with the laser beam L 1 . The laser beam L 1  passing through the anode substrate  111  does not heat the anode substrate  111 . However, the anode substrate  111  is heated through the heating of the ring-less getter G 11 . Thus, the portion of the anode substrate  111 , which is in contact with the ring-less getter G 11 , melts. In such a state, both the ring-less getter G 11  and the anode substrate  11  are cooled, the molten portions thereof are solidified so that the ring-less getter G 11  is securely fixed to the anode substrate  111 . 
     A conventional getter material may be used for the ring-less getter G 11 . However, when a mixture of BaAl4, MaAl and Ni, Ti, Fe are used, it reacts chemically with Al, Ni, so that the reaction heat generates. Since the reaction heat increases the ring-less getter G 11  to a temperature of 1050° C., the inner surface of the anode substrate  111  (which is in contact with the ring-less getter G 11 ) fuses rapidly. The ring-less getter material having a low transmittance (other than total transmission) of a laser beam, that is, an optical energy, is suitably selected. 
     The inventor of this application focused an attention on the fact that as the laser beam L 1  heats the ring-less getter G 11  through the glass anode substrate  111 , the anode substrate  111  thermally melts through the heating of the ring-less getter G 11 . Thus, the present inventor invented the method of bonding the ring-less getter G 11  to the anode substrate  111  through the irradiation of the laser beam L 1 . 
     The laser beam L 1  may be illuminated through the laser marker system or the dot spot system. The laser may be YAG laser, excimer laser, carbon dioxide laser, or the like. 
     The glass substrate can pass wavelengths ranging from visible rays to 1.06 μm used with the YAG laser. Particularly, the glass substrate indicating a high transmittance of 1.06 μm is effective for the YAG laser. 
     The present embodiment uses a disc ring-less getter having a diameter of 2 mm and a thickness of 0.5 mm and a flat ring-less getter having a size of 2 mm×10 mm and a thickness of 0.5 mm. The ring-less getter is fixed to a 1.1 mm-thick soda glass substrate. A non-alkali glass may be used for the glass substrate. 
     In the laser marker system, a YAG laser is used and 17 W, 10 kH, and 20 mm/second are set for the laser beam conditions. 
     In the laser marker system, the adhesive strength (or the shear strength) of the disc ring-less getter is 20 N and the adhesive strength of the flat ring-less getter is 60 N or more. With the same size and the same conditions, the adhesive strength in the laser marker system was improved 20 times, compared with the adhesive strength of the ring-less getter bonded with the fritted glass. Here, the shear strength means the force of peeling off the ring-less getter from the anode substrate when a force is applied from the side surface thereof to a ring-less getter bonded on the anode substrate in the direction in parallel with the anode substrate. In other words, the shear strength means a maximum force for peeling off a ring-less getter. 
     As shown in  FIG. 6(   b ), after the ring-less getter G 11  is bonded to the anode substrate  111 , a fluorescent display tube is assembled through the conventional assembly process and then is evacuated for sealing. 
     As shown in  FIG. 6(   c ), the laser beam L 2  is irradiated onto the ring-less getter G 11  from the outside the front substrate, that is, from the outside of the envelope (or hermetic container) of the fluorescent display tube. Thus, the ring-less getter G 11  activates (flushes) and the particles of the evaporated (flushed) getter material sputter in the direction of the arrow F. As a result, a getter mirror film (not shown) is formed over an inner surface of the front substrate  112 , that is, over an inner surface of the envelope of the fluorescent display tube. The laser beam L 2  may impinge onto the side surface of the ring-less getter G 11  from the outside of the side plate  114  so that the getter mirror film of Ba can be formed over an inner surface of the side plate  114 . 
     With the illumination conditions of 8 W, 5 kH, and 100 mm/second, the laser beam is irradiated according to the laser marker system. 
     In the above-mentioned embodiments, the example has been explained where the ring-less getter is bonded to the anode substrate, the front substrate, the side plate, or the grid holding intermediate substrate. However, the member for fixing the ring-less getter is not limited only to the above-embodiments. The ring-less getter can be fixed with the glass member disposed in the envelope of a fluorescent display tube, for example, with a glass pillar (support or spacer) or a glass plate which can prevent an evaporated getter material from being sputtered toward the display surface, the electrodes, or others. In the present invention, a glass member for fixing the ring-less getter is called a glass substrate. 
     In each above-mentioned embodiment, the example has been explained where a ring-less getter is fixed to each glass substrate. However, the ring-less getter may be fixed to plural glass substrates. The glass substrate, on which a ring-less getter is fixed, as well as the location for fixing may be suitably selected according to the configuration of a fluorescent display tube. 
     The example of bonding and flushing the ring-less getter with the laser beam has been explained. However, an optical energy, except laser beam, may be used. 
     In each embodiment, the evaporation-type getter has been explained. However, a non-evaporation-type getter containing a main constituent such as Zr, Ti, Ta, and the like may be employed. The non-evaporation-type getter is heated to an activation temperature, without flushing, to provide the gas adsorption capability. However, an optical energy may be used to heat the non-evaporation-type getter. 
     In each embodiment, a fluorescent display tube has been explained. However, field emission fluorescent displays, luminous tubes for large-screen display devices, luminous tubes for fluorescent print heads, electron tube, such as CRTs, belonging to vacuum tubes, electron tubes, such as PDPs, belonging to discharge tubes, or electron devices such as ELDs may be used in each embodiment. When the electron device is either an electron tube belonging to a discharge tube or an ELD, a non-evaporation type ring-less getter is used. The PDP employs a getter material that can adsorb nitrogen and oxygen. The FED, particularly, an organic FED uses a getter material that can adsorb moisture. In the organic FED, organic luminous elements each having a first electrode, an organic layer including a luminous layer formed on the first electrode, and a second electrode formed on the organic layer, are contained in a hermetic container. Moreover, in the FED, the hermetic container is formed of a resin such as plastic or polymer film. When the resin is transparent or is transparent to an optical energy, the ring-less getter can be bonded onto the inner surface of the hermetic container with the optical energy, without heating the resin. 
     In each embodiment, the case where has been described all substrates including an anode substrate, a front substrate, a side plate, or a grid holding intermediate substrate are made of glass. However, it is not always required that all the substrates are made of glass. It is merely required that the substrate to which the ring-less getter is bonded is at least of glass. Alternatively, it is merely requires that the portion of a substrate at which a ring-less getter is bonded is at least of glass. 
     Similarly, when the ring-less getter is activated, all portions or part of a substrate confronting the ring-less getter (or of a substrate allows which the passing of an optical energy irradiated to a ring-less getter) may be of glass. 
     INDUSTRIAL APPLICABILITY 
     The ring-less getter of the present invention has a simplified structure and can be bonded onto a glass substrate merely by irradiating the laser beam onto the ring-less getter. Accordingly, the mounting work can be simplified and automated easily. 
     According to the present invention, since the ring-less getter can be bonded to a glass substrate, the degree of freedom becomes larger when a ring-less getter is disposed. For example, the ring-less getter can be bonded onto metallization (an electrode wiring conductor) such as an anode wiring conductor. 
     In the present invention, both the ring-less getter and the glass substrate are once fused and solidified, the ring-less getter can be rigidly securely bonded onto the glass substrate. 
     Moreover, since the fritted glass is not used to bond the ring-less getter, it can be avoided that gases produced from the fritted-glass during the flushing of the ring-less getter block the electron emission of an electron source such as a filament. 
     According to the present invention, the laser beam bonds the ring-less getter onto the glass substrate and flushes the ring-less getter. Therefore, by merely changing the laser beam illumination conditions, the same laser beam illuminator can be shared for the mounting and flushing of a ring-less getter. 
     Moreover, the ring-less getter, which is made through merely press-molding the getter material powder, has its simple structure and can be fabricated easily and inexpensively. Moreover, the ring-less getter can be molded in a given shape and hence can be fabricated in the shape corresponding to a dead space in the electron device. Accordingly, a combination of ring-less getters different in shape enables effectively using dead spaces in the electron device. 
     Moreover, the press-molded ring-less getter can be set to a given thickness. Therefore, the ring-less getter formed of a getter material enough to adsorb the residual gases can be mounted in the electron device.