Abstract:
A light emission display having a housing including at least two glass members thermally glued to one another at a predetermined atmospheric pressure to form a plurality of cavities inside the housing, and at least one of a gas and a light emitting substance contained within the cavities. Electrodes are located between the glass members and protrude into each cavity in only a coplanar manner with respect to a main surface of one of the glass members. An input signal is supplied to the electrodes resulting in selective light emission from the cavities.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display and a method for producing the same, based on the principle of the electronic tube which utilizes the discharge light emission of at least one of a gas and a light emitting substance enclosed in a formed product made of, for example, a glass material. 
     2. Description of the Related Art 
     In general, the light source, which utilizes the discharge light emission of at least one of the gas and the light emitting substance enclosed in a tube made of glass, includes electronic tubes such as mercury lamps, fluorescent tubes, sodium lamps, carbon arc lamps, zirconium discharge lamps, neon tubes, and flash discharge lamps. 
     The electronic tube as described above is manufactured, for example, such that an anode bar is fused to one end of a cylindrical glass tube, and then a cathode bar is fused to the other end of the glass tube in a predetermined gas atmosphere (atmosphere containing the gas to be enclosed) to enclosed the predetermined gas in the glass tube. 
     It is contemplated that such an electronic tube is utilized to display, for example, images and characters at the outdoor. 
     In such a situation, it is conceived that a large number of electronic tubes are arranged so that the light is selectively emitted from the electronic tubes. However, the respective electronic tubes exist as single members. Therefore, when the large number of electronic tubes are arranged, the scale is inevitably large. As a result, problems arise in that the installation space is enlarged, the wiring operation is complicated, and the production cost becomes expensive. 
     Under the circumstances, it is expected that the electronic tube itself is allowed to have a miniature size. However, if the electronic tube is miniaturized, then the distance between the anode and the cathode is decreased, and the pressure at the inside of the glass tube is further increased during the light emission. Therefore, it is necessary to increase the strength of the glass tube in association with the miniaturization of the electronic tube. 
     SUMMARY OF THE INVENTION 
     The present invention has been made taking the foregoing problems into consideration, an object of which is to provide a display which makes it possible to simultaneously realize the integration and the miniaturization of the electronic tube and present the display expression for information transmission at a high brightness. 
     Another object of the present invention is to provide a method for producing a display, in which it is possible to easily produce the display which makes it possible to simultaneously realize the integration and the miniaturization of the electronic tube and present the display expression for information transmission at a high brightness. 
     According to the present invention, there is provided a display comprising a housing formed by confronting at least two glass members with each other in a predetermined atmosphere and thermally gluing them under a pressure; at least one or more cavities formed in the housing and enclosed with at least one of a gas and a light emitting substance at its inside; and mutually confronting electrodes provided for the cavity interposed therebetween; wherein at least two or more of the cavities are arranged by the aid of at least one of the housing; and an output corresponding to an inputted signal is displayed in accordance with selective light emission effected in the cavities. 
     The cavity, in which at least one of the gas and the light emitting substance is enclosed, is formed in the housing which is manufactured by thermally gluing the glass members under the pressure. The electric power is applied to the electrodes which are opposed to one another with the cavity interposed therebetween. Thus, the discharge light emission is effected by at least one of the gas and the light emitting substance enclosed in the cavity. That is, one cavity functions as one electronic tube. 
     In the present invention, at least one housing is used to arrange at least two or more of the cavities. Therefore, when the cavities are arranged in conformity with the number of picture elements (image pixels) to be displayed, the discharge light emission is selectively effected by at least one of the gas and the light emitting substance enclosed in the cavities corresponding to the number of the picture elements, by selectively applying the electric power to the large number of electrodes confronting with each other with the cavities interposed therebetween, in accordance with the inputted image signal. Thus, the image, which corresponds to the image signal, is displayed on the display surface of the housing. 
     In this arrangement, the cavities are formed by thermally gluing the glass members under the pressure. Therefore, it is possible to integrate the large number of cavities at a high degree of integration, in accordance with which the miniaturization of the display can be easily realized. 
     As described above, according to the display concerning the present invention, it is possible to simultaneously realize the integration and the miniaturization of the electronic tube and present the display expression for information transmission at a high brightness. 
     In the arrangement described above, it is preferable that at least the glass member of the glass members for constructing the housing, which is disposed on a display side, is light-transmissive. Accordingly, the display surface of the housing is allowed to have the light-transmissive property. Therefore, it is possible to make the display expression at a high brightness for the output corresponding to the input signal. Thus, the display is most suitable, for example, as an electronic bulletin board installed at the outdoor. 
     In the arrangement described above, it is also preferable that the glass member of the glass members for constructing the housing, which does not contribute to display expression, is not light-transmissive. In this arrangement, the light components directed to the display surface of the housing, which are included in the light components radiated by the discharge light emission effected in the cavities, are radiated to the outside through the glass member having the light-transmissive property. However, the light components, which are directed to the surfaces other than the display surface of the housing, are absorbed by the glass member having no light-transmissive property. 
     Accordingly, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities. Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     In the arrangement described above, it is also preferable that a light-reflective film is formed on a surface portion except for a surface portion disposed on a display side, of an inner wall surface of the cavity. In this arrangement, the light components directed to the display surface of the housing, which are included in the light components radiated by the discharge light emission effected in the cavities, are radiated to the outside through the glass member having the light-transmissive property. However, the light components, which are directed to the surfaces other than the display surface of the housing, are reflected by the light-reflective surface. As a result, almost all of the light components generated in the cavity are directed to the display surface of the housing. Thus, it is possible to achieve a higher degree of brightness. Also in this arrangement, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities. Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     Further, a light-shielding substance may be allowed to intervene between the cavities. Accordingly, it is also possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities. 
     In the arrangement described above, it is also preferable that the electrodes are constructed by lead wires fixed on a surface at which the glass members contact with each other. Alternatively, the electrodes may be constructed by thin films formed by printing on a surface at which the glass members contact with each other. Especially, when the electrodes are constructed by the thin films, then the labor for wiring arrangement can be eliminated, and it is possible to simplify the production steps. Further, the positioning can be easily performed in order to confront the electrodes with each other with the cavity interposed therebetween. 
     In the arrangement described above, it is also preferable that the glass member to be used has a bending strength of not less than 1000 kgf/cm 2 . 
     For example, in the case of the display in which argon, mercury or the like is enclosed in the cavity, the glass member having a bending strength of about 1000 kgf /cm 2  is used. In the case of the display in which the gas such as xenon capable of obtaining a high brightness is enclosed, the glass member having a bending strength of about 3000 kgf/cm 2  is preferably used. 
     In general, in order to improve the resolution of the display expression, it is necessary to increase the number of cavities which function as electronic tubes. However, considering the miniaturization in such a situation, it is conceived that the respective cavities are reduced in size. If the size of the respective cavities is reduced, the pressure in the cavity is increased during the light emission in accordance therewith. However, when the glass member satisfies the condition for the bending strength as described above, a formed product is obtained, which is sufficiently capable of withstanding the pressure in the cavity. Thus, it is possible to avoid the inconvenience such as the light emission defect. 
     In the arrangement described above, it is also preferable that the glass member to be used has a coefficient of thermal expansion which is substantially zero or which is near to a coefficient of thermal expansion of the electrode. In this arrangement, the heat resistance is excellent, and the display is advantageous in resistance to the heat cycle relevant to the repetition of discharge light emission of at least one of the gas and the light emitting substance enclosed in the cavity. 
     According to another aspect of the present invention, there is provided a method for producing a display, comprising a first step of forming, by press forming on at least one of glass members, recesses for constructing cavities for enclosing at least one of a gas and a light emitting substance; a second step of providing electrodes on a contact surface of the glass member; and a third step of confronting respective contact surfaces of at least two of the glass members with each other so that they are thermally glued under a pressure in a predetermined atmosphere to manufacture a housing including at least one cavity at its inside, and thus the display is produced wherein at least two or more of the cavities are arranged by the aid of at least one of the housing, and an image corresponding to an inputted image signal is displayed in accordance with selective light emission effected in the cavities. 
     According to the method for producing the display concerning the present invention, it is possible to simultaneously realize the integration and the miniaturization of the electronic tube, and it is possible to present the display expression for information transmission at a high brightness. 
     In the present invention, it is preferable that a glass member having a light-transmissive property is used as at least the glass member of the glass members for constructing the housing, which is disposed on a display side. Accordingly, the display surface of the housing is allowed to have the light-transmissive property. Therefore, it is possible to make the display expression at a high brightness for the output corresponding to the input signal. Thus, the display is most suitable, for example, as an electronic bulletin board installed at the outdoor. 
     In the production method described above, it is preferable that a glass member having no light-transmissive property is used as the glass member of the glass members for constructing the housing, which does not contribute to display expression. It is also preferable that before the third step, a light-reflective film is formed on a surface portion except for a surface portion disposed on a display side, of an inner wall surface of the cavity. In this arrangement, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities. Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. It is also preferable that a light-shielding substance is allowed to intervene between the cavities. 
     In the second step, it is preferable that the electrodes are provided by fixing lead wires on the contact surface of the glass member. It is also preferable that the electrodes are provided by forming a thin film by means of printing on the contact surface of the glass member. 
     It is also preferable that a glass member having a bending strength of not less than 1000 kgf/cm 2  is used as the glass member. It is also preferable that a glass member having a coefficient of thermal expansion which is substantially zero or which is near to a coefficient of thermal expansion of the electrode is used as the glass member. 
     The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view illustrating an arrangement of a display according to a first embodiment; 
     FIG. 2 shows a perspective view illustrating, with partial omission, a wiring arrangement state of the display according to the first embodiment; 
     FIG. 3 shows a block diagram illustrating an arrangement of a driving unit used for the display according to the first embodiment; 
     FIG. 4 shows an exploded sectional view illustrating, with partial omission, the arrangement of the display according to the first embodiment; 
     FIG. 5 shows a longitudinal sectional view illustrating, with partial omission, an arrangement of a light emitting element according to the first embodiment; 
     FIG. 6 shows a perspective view illustrating, with partial omission, a first exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 7 shows a sectional view illustrating, with partial omission, the first exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 8 shows a perspective view illustrating, with partial omission, a second exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 9 shows a sectional view illustrating, with partial omission, the second exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 10 shows a perspective view illustrating, with partial omission, a third exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 11 shows a sectional view illustrating, with partial omission, the third exemplary method for fixing the lead wire on the contact surface of the housing member; 
     FIG. 12 illustrates the function to avoid the crosstalk between the cavities; 
     FIG. 13 shows a block diagram depicting steps of a method for producing the display according to the first embodiment; 
     FIG. 14 shows a characteristic curve illustrating the forming temperature for the glass member and the elongation percentage of the glass member; 
     FIG. 15 shows a graph illustrating a time schedule for the heat treatment performed to cause crystallization; 
     FIG. 16 shows a longitudinal sectional view illustrating, with partial omission, a first modified embodiment of the display according to the first embodiment; 
     FIG. 17 shows a longitudinal sectional view illustrating, with partial omission, a second modified embodiment of the display according to the first embodiment; 
     FIG. 18 shows an exploded sectional view illustrating, with partial omission, a third modified embodiment of the display according to the first embodiment; 
     FIG. 19 shows a longitudinal sectional view illustrating, with partial omission, the third modified embodiment of the display according to the first embodiment; 
     FIG. 20 shows a block diagram depicting steps of a method for producing the display according to the third modified embodiment; 
     FIG. 21 shows a perspective view illustrating an arrangement of a display according to a second embodiment; 
     FIG. 22 shows a perspective view illustrating, with partial omission, a wiring arrangement state of the display according to the second embodiment; 
     FIG. 23 shows a longitudinal sectional view illustrating, with partial omission, the display according to the second embodiment; 
     FIG. 24 shows a sectional view taken along a line XXIV—XXIV shown in FIG. 23; 
     FIG. 25 shows a sectional view illustrating, with partial omission, a first exemplary method for forming a thin film pattern on the contact surface of the housing member; 
     FIG. 26 shows a sectional view illustrating, with partial omission, a second exemplary method for forming a thin film pattern on the contact surface of the housing member; 
     FIG. 27 shows a sectional view illustrating, with partial omission, a third exemplary method for forming a thin film pattern on the contact surface of the housing member; 
     FIG. 28 shows a longitudinal sectional view illustrating, with partial omission, a first modified embodiment of the display according to the second embodiment; 
     FIG. 29 shows a longitudinal sectional view illustrating, with partial omission, a second modified embodiment of the display according to the second embodiment; 
     FIG. 30 shows a longitudinal sectional view illustrating, with partial omission, a third modified embodiment of the display according to the second embodiment; 
     FIG. 31 shows a longitudinal sectional view illustrating, with partial omission, a fourth modified embodiment of the display according to the second embodiment; 
     FIG. 32 shows a schematic arrangement illustrating, with partial omission, a display according to a third embodiment; 
     FIG. 33 shows a schematic arrangement illustrating, with partial omission, a display according to a fourth embodiment; 
     FIG. 34 shows a schematic arrangement illustrating, with partial omission, a display according to a fifth embodiment; 
     FIG. 35 illustrates a first example arranged for the purpose of color display; 
     FIG. 36 illustrates a second example arranged for the purpose of color display; 
     FIG. 37A shows a timing chart illustrating a case in which the ratio of light emission time of RGB is 1:1:1; 
     FIG. 37B shows a timing chart illustrating a case in which the ratio of light emission time of RGB is 4:1:5; and 
     FIG. 38 shows a perspective view illustrating an arrangement of a display according to a sixth embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Explanation will be made below with reference to FIGS. 1 to  38  for illustrative embodiments of the display and the method for producing the same according to the present invention. 
     At first, as shown in FIG. 1, a display  10 A according to the first embodiment comprises a housing  16  which is formed such that respective first principal surfaces of a rectangular upper housing member  12  and a rectangular lower housing member  14  made of a glass material are allowed to make contact with each other to thermally glue them by press under a pressure in a predetermined atmosphere, cavities  18  which are formed to have a number corresponding to picture elements (image pixels) in the housing  16  and which include at least one of a gas and a light emitting substance enclosed therein, and electrode wires  20 ,  22  (anodes and cathodes) which are provided for the respective picture elements and which have their ends confronting with each other with the cavities  18  being interposed therebetween. 
     The electrode wires  20 , which constitute the respective anodes, are connected to vertical selection lines  24  arranged in the horizontal direction. The electrode wires  22 , which constitute the respective cathodes, are connected to signal lines  26  arranged in the vertical direction. In the first embodiment, the vertical selection lines  24 , the signal lines  26 , and the electrode wires  20 ,  22  are composed of lead wires respectively. 
     As shown in FIG. 2, when the vertical selection line  24  and the signal line  26  are arranged and wired, a paste  28  made of a glass material is formed at a portion of intersection between the vertical selection line  24  and the signal line  26  to insulate the vertical selection line  24  from the signal line  26 . 
     As shown in FIG. 3, a driving unit  30  for the display  10 A comprises a vertical scanning circuit  32  composed of, for example, a shift register for selectively supplying a driving signal to the vertical selection line  24  (connected in series, for example, to the electrode wire  20  arranged for the cavity  18  for each row) to successively select the cavity  18 , for example, in the unit of one row, a horizontal scanning circuit  34  composed of, for example, a shift register for outputting a data signal in parallel to the signal line  26  to supply the data signal respectively to the electrode wire  22  of each cavity  18  on a selected column (column of selection), and a signal control circuit  36  for controlling the vertical scanning circuit  32  and the horizontal scanning circuit  34  on the basis of an image signal Sv and a synchronization signal Sd to be inputted. 
     When the display  10 A according to the first embodiment is driven, the image is displayed by allowing the cavity  18  to perform two basic operations (ON selection and OFF selection). 
     Specifically, the group of picture elements (the group of cavities) are successively selected one row by one row, for example, such that the first row, the second row, . . . and nth row are selected for every scanning period 1H in accordance with the supply of the electric potential to the vertical selection line  24  effected by the vertical scanning circuit  32  on the basis of the input of the image signal Sv and the synchronization signal Sd into the signal control circuit  36 . The signal line  26  on the selected row, which relates to the cavity  18  to be subjected to the ON selection, is supplied with the electric potential from the horizontal scanning circuit  34  at a predetermined selection point of time. 
     As a result, a predetermined voltage, which is sufficient to allow at least one of the gas and the light emitting substance enclosed in the cavity  18  to cause the discharge light emission, is applied between the electrode wires  20 ,  22  relating to the cavity  18  subjected to the ON selection by the vertical scanning circuit  32  and the horizontal scanning circuit  34 . The light is emitted from the concerning cavity  18 . The amount of light emission obtained in this situation is changed by the voltage level applied between the electrode wires  20 ,  22 . Therefore, it is possible to perform the gradation control based on the voltage modulation system. 
     Components for constructing the display  10 A will now be explained with reference to FIGS. 4 to  11 . At first, as shown in FIGS. 4 and 5, the upper housing member  12  is formed to have the rectangular plate-shaped configuration. The lower housing member  14  is formed with a recess  40  which has, for example, a rectangular configuration and which is formed at a central portion of its first principal surface  14   a.    
     The upper housing member  12  and the lower housing member  14  are allowed to make contact with each other while confronting the first principal surfaces  12   a,    14   a  with each other to thermally glue them by press under a pressure in a predetermined atmosphere. Thus, the housing  16  (formed product) is manufactured, which has the cavity  18  formed by the recess  40  at the inside. Therefore, the surface portion other than the recess  40 , of the first principal surface  14   a  of the lower housing member  14  functions as the contact surface  14   a  to make contact with the upper housing member  12 . 
     Before the upper housing member  12  and the lower housing member  14  are allowed to make contact with each other with the first principal surfaces  12   a,    14   a  confronting with each other, for example, a large number of vertical selection lines  24  and signal lines  26  are wired and fixed on the contact surface  14   a  of the lower housing member  14 . The electrode wires  20  for constructing the anodes and the electrode wires  22  for constructing the cathodes are fixed with their respective ends exposed to the recesses  40 . Accordingly, when the upper housing member  12  and the lower housing member  14  are thermally glued by press under the pressure with each other, the anode and the cathode, which are formed by the electrode wires  20 ,  22  respectively for each picture element, are confronted with each other with the cavity  18  interposed therebetween. In this embodiment, in order to ensure the discharge light emission in the cavity  18 , it is more preferable to allow the respective ends of the electrode wires to protrude into the cavity  18 . 
     The method for wiring and fixing the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  on the contact surface  14   a  of the lower housing member  14  includes, for example, a method in which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are fixed by the aid of a paste  50  made of a glass material applied to the contact surface  14   a  as shown in FIGS. 6 and 7, a method in which grooves  52  for lead wires are previously formed at portions for wiring the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22 , and the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are arranged and fixed in the grooves  52  respectively as shown in FIGS. 8 and 9, and a method in which the paste  50  made of the glass material is applied to the grooves  52 , and the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are fixed in the grooves  52  as shown in FIGS. 10 and 11. The glass material pastes  28 ,  50  are preferably a paste having the same composition as that of the glass material for constructing the housing  16 , for example, in view of the thermal expansion. More preferably, in order to improve the operability, the melting point of the glass is slightly lowered. When the glass material paste  50  is used, it is preferable that the glass material paste  50  is also applied to the contact surface  12   a  of the upper housing member  12 . 
     In this embodiment, crystallized glass is used as the glass material for constructing the upper housing member  12  and the lower housing member  14 . Specifically, this embodiment uses a glass material having its trade name of “Miraclon” (registered trademark) produced by NGK Insulators, Ltd. Miraclon (registered trademark) includes glass ceramic products (Miraclon PP and Miraclon PH) and a chemical strengthening glass product (Miraclon PC). 
     The glass ceramic product is obtained such that a blended preparation having a specified composition is melted and glassified at a high temperature, which is formed in the same manner as in the ordinary glass production method, followed by a heat treatment under a specified condition to make conversion into an aggregate composed of a large number of uniform microcrystals. The chemical strengthening glass product is obtained such that the glass surface layer is subjected to ion exchange. 
     The characteristics will now be briefly explained for the crystallized glass specified by Miraclon (registered trademark). 
     At first, Miraclon PP is obtained by depositing, in glass, about 1 μm of microcrystals of lithium disilicate (Li 2 O·2SiO 2 ) and β-spodumene (Li 2 O·Al 2 O 3 ·4SiO 2 ), and it has the following features. That is, the appearance is white and opaque. Especially, the bending strength is 3500 kgf/cm 2  which is extremely strong and which is not less than three times those of the glass and the porcelain. 
     Miraclon PH-1 is obtained by depositing, in glass, about 1 μm of microcrystals of β-spodumene (Li 2 O·Al 2 O 3 ·4SiO 2 ), and it has the following features. That is, the appearance is white and opaque. The coefficient of thermal expansion is about 11×10 −7 /° C. which is small. Miraclon PH-1 is strong against heat shock. 
     Miraclon PH-3 is obtained by depositing, in glass, about 1 μm of β-quartz type microcrystals (Li 2 O·Al 2 O 3 ·2SiO 2 ), and it has the following features. That is, the appearance is colorless and transparent. The coefficient of thermal expansion is substantially zero. Therefore, Miraclon PH-3 is extremely strong against heat shock. Miraclon PH-3 is not broken even when it is red-heated to 800° C. followed by introduction into water at 0° C. 
     Miraclon PC is chemical strengthening glass obtained by ion exchange of Li + ⇄Na +  for the glass surface layer, and it has the following feature. Especially, the bending strength is 5200 kgf/cm 2  which is extremely strong. 
     In the first embodiment, the glass material having the light-transmissive property, for example, Miraclon PH-1 is used for the upper housing member  12 , and the glass material having no light-transmissive property, for example, Miraclon PH-3 is used for the lower housing member  14 . 
     As described above, in the display  10 A according to the first embodiment, the cavity  18 , in which at least one of the gas and the light emitting substance is enclosed, is formed in the housing  16  manufactured such that the upper housing member  12  and the lower housing member  14  composed of the glass material are thermally glued by press under the pressure. The electric power is applied to the anode and the cathode (electrode wires  20 ,  22 ) confronting with each other with the cavity  18  interposed therebetween. Thus, the discharge light emission is effected by at least one of the gas and the light emitting substance enclosed in the cavity  18 . That is, one cavity  18  functions as one electronic tube. 
     Especially, in the first embodiment, the large number of cavities  18  are formed and arranged in the single housing  16  in conformity with the number of picture elements. Therefore, the electric power is selectively applied to the large number of electrode wires  20 ,  22  opposed to one another with the cavities  18  interposed therebetween, in response to the inputted image signal. Thus, the discharge light emission is selectively effected by at least one of the gas and the light emitting substance enclosed in the cavities  18  of the number corresponding to the number of picture elements. Consequently, the image corresponding to the image signal is displayed on the display surface of the housing  16  (the second principal surface of the upper housing member  12  in this embodiment). 
     In this embodiment, the cavities  18  are formed by the thermal adhesion of the glass members under the pressure. Accordingly, it is possible to integrate the large number of cavities  18  at a high degree of integration, in accordance with which it is also possible to easily realize the miniaturization of the display  10 A. 
     As described above, according to the display  10 A concerning the first embodiment, it is possible to simultaneously realize the integration and the miniaturization of the electronic tube, and it is possible to present the display expression for information transmission at a high brightness. Further, it is also contemplated to make application to color display. 
     Especially, in this embodiment, the upper housing member  12  on the display side, of the housing members  12 ,  14  for constructing the housing  16  is made of the glass material having the light-transmissive property. Therefore, the display surface of the housing  16  has the light-transmissive property. Accordingly, it is possible to display at a high brightness, the image corresponding to the image signal Sv. Thus, the display  10 A is most suitable, for example, as an electronic bulletin board installed at the outdoor. 
     In this embodiment, the lower housing member  14  of the housing members  12 ,  14  for constructing the housing  16 , which does not contribute to the display expression, is made of the glass material having no light-transmissive property. In this arrangement, as shown in FIG. 12, the light components directed to the display surface of the housing  16 , which are included in the light components radiated by the discharge light emission effected in the cavities  18 , pass through the glass material having the light-transmissive property, and they are radiated to the outside. However, the light components directed to the surfaces other than the display surface of the housing  16  are absorbed by the glass material which has no light-transmissive property. In FIG. 12, the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are omitted from the illustration. 
     As a result, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities  18 . Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     Further, the display  10 A according to the first embodiment uses the glass material having the bending strength of not less than 1000 kgf/cm 2  as the glass material for constructing the upper housing member  12  and the lower housing member  14 . Therefore, it is possible to obtain the following effects. 
     That is, in order to improve the resolution of the display expression, it is necessary to increase the number of cavities  18  which function as electronic tubes. However, considering the miniaturization, it is conceived that the respective cavities  18  are reduced in size. 
     If the size of the respective cavities  18  is reduced, the pressure in the cavity  18  is increased during the light emission in accordance therewith. However, when the glass member satisfies the bending strength as described above, the formed product (housing  16 ) is obtained, which is sufficiently capable of withstanding the pressure in the cavity  18 . Thus, it is possible to avoid the inconvenience such as the light emission defect. 
     The glass material having a bending strength of about 1000 kgf/cm 2  is used for the display in which, for example, argon or mercury is enclosed in the cavity. The glass material having a bending strength of about 3000 kgf/cm 2  is preferably used for the display in which the gas such as xenon to obtain a high brightness is enclosed in the cavity. 
     The display  10 A according to the first embodiment is allowed to use the glass material in which the coefficient of thermal expansion is substantially zero, or it is near to the coefficient of thermal expansion of the electrode material for constructing, for example, the electrode wire. In this arrangement, the heat resistance is excellent, and the display  10 A is advantageous in resistance to the heat cycle relevant to the repetition of discharge light emission of at least one of the gas and the light emitting substance enclosed in the cavity  18 . 
     Next, a method for producing the light emitting element  10 A according to the first embodiment will be explained with reference to a flow chart shown in FIG.  13 . 
     At first, in the step S 1 , various composition components are blended in order to obtain the desired crystallized glass. For example, when Miraclon PP-1 and Miraclon PP-4 are obtained, the blending is carried out to give 79% by weight of SiO 2 , 6.0% by weight of Al 2 O 3 , 12.5% by weight of Li 2 O, 2.5% by weight of K 2 O, 3.0% by weight of P 2 O 5 , and 0.3% by weight of As 2 O 3 . 
     When Miraclon PH-1, Miraclon PH-3, and Miraclon PH-4 are obtained, the blending is carried out to give 65.7% by weight of SiO 2 , 22.7% by weight of Al 2 O 3 , 4.2% by weight of Li 2 O, 0.5% by weight of Na 2 O, 0.3% by weight of K 2 O, 1.4% by weight of P 2 O 5 , 0.5% by weight of MgO, 1.7% by weight of TiO, 0.9% by weight of As 2 O 3 , 2.4% by weight of ZrO 2 , and 0.2% by weight of Sb 2 O 3 . 
     When Miraclon PC-4 is obtained, the blending is carried out to give 62.9% by weight of SiO 2 , 17.2% by weight of Al 2 O 3 , 3.5% by weight of Li 2 O, 5.8% by weight of Na 2 O, 1.9% by weight of CaF 2 , 1.0% by weight of TiO, 7.7% by weight of B 2 O 3 , and 0.3% by weight of As 2 O 3 . 
     Subsequently, in the step S 2 , the blended preparation is heated and melted at a temperature of 1400 to 1500° C. Subsequently, in the step S 3 , the melted blended preparation is quenched and quickly cooled with water, oil or the like without causing crystallization in the same manner as in the ordinary glass production method. After that, in the step S 4 , the cooled blended preparation is processed to have a plate-shaped configuration to prepare a source plate for the upper housing member  12  and the lower housing member  14 . 
     Subsequently, in the step S 5 , the source plate is press-formed to produce the plate-shaped upper housing member  12  and the lower housing member  14  having the recess  40  at the central portion of the first principal surface is  14   a.  The press forming is performed at a temperature of not less than a softening point Ts of the source plate. The softening point Ts is a temperature at which the viscosity of the source plate is 4.5×10 7  poise. In this embodiment, as shown in FIG. 14, for example, the process is carried out at a temperature which is higher by about 40° C. to 50° C. than the yield temperature T d  at which the elongation percentage is maximum. T G  in FIG. 14 represents the temperature at which the melted glass begins to be solidified, i.e., the transition temperature. 
     Subsequently, in the step S 6  shown in FIG. 13, the upper housing member  12  and the lower housing member  14 , which have been manufactured by the press forming described above, are cooled, for example, to the room temperature. After that, in the step S 7 , the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are wired and fixed, for example, on the contact surface  14   a  of the lower housing member  14 . As described above, the method for fixing the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  includes, for example, a method in which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are fixed by the aid of the paste  50  made of the glass material applied to the contact surface  14   a  of the lower housing member  14  (see FIGS.  6  and  7 ), a method in which the grooves  52  for lead wires are previously formed on the contact surface  14   a  of the lower housing member  14 , and the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are arranged and fixed in the grooves  52  respectively (see FIGS.  8  and  9 ), and a method in which the paste  50  made of the glass material is applied to the grooves  52 , and the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are fixed in the grooves  52  (see FIGS.  10  and  11 ). 
     Subsequently, in the step S 8 , the upper housing member  12  and the lower housing member  14  are allowed to make contact with each other with their first principal surfaces (contact surfaces)  12   a,    14   a  opposing to one another to thermally glue them by press under a pressure in a predetermined atmosphere, for example, a xenon atmosphere at a high pressure (1 to 20 atms). Thus, the housing  16  is manufactured, which includes, at its inside, the cavities  18  formed by the first principal surface  12   a  of the upper housing member  12  and the recesses  40  of the lower housing member  14 . The press thermal gluing process under the pressure is also performed at a temperature which is higher by about 40° C. to 50° C. than the yield temperature T D , in the same manner as in the press forming performed in the step S 5 . 
     Subsequently, in the step S 9 , the heat treatment is performed in order that the crystalline nucleuses are generated in the manufactured housing  16  to cause crystallization. Thus, the display  10 A according to the first embodiment is produced. 
     An example of the heat treatment will be explained. As shown in FIG. 15, the temperature is raised from the room temperature to the primary crystallization temperature t 1  at a temperature-raising speed of 50° C. to 200° C./hour, followed by being held for a certain period of time T 1 . Accordingly, the crystalline nucleuses are formed in the housing  16 . After that, the temperature is raised to the secondary crystallization temperature t 2  at a temperature-raising speed of 50° C. to 200° C./hour, followed by being held for a certain period of time T 2 . Accordingly, the crystals grow in the housing  16 . Subsequently, the temperature is lowered to the room temperature at a temperature-lowering speed of, for example, 50° C. to 200° C. /hour. 
     The application of the heat treatment for the purpose of crystallization as described above allows the housing  16  to be converted into an aggregate of a large number of uniform microcrystals. As a result, it is possible to obtain the high bending strength which is not less than three times that of the glass. 
     Next, several modified embodiments of the display  10 A according to the first embodiment will be explained with reference to FIGS. 16 to  20 . 
     At first, as shown in FIG. 16, a display  10 Aa according to a first modified embodiment comprises a recess  60  provided on the upper housing member  12  as well. In this embodiment, the cavity  18  is formed by the recess  60  of the upper housing member  12  and the recess  40  of the lower housing member  14 . 
     Next, as shown in FIG. 17, a display  10 Ab according to a second modified embodiment comprises a recess  60  provided on only the upper housing member  12 . In this embodiment, the cavity  18  is formed by the recess  60  and the first principal surface  14   a  of the lower housing member  14 . 
     Next, as shown in FIG. 18, a display  10 Ac according to a third modified embodiment comprises three stacked housing members. The upper housing member  12  is formed to have a rectangular plate-shaped configuration. The lower housing member  14  has a rectangular contour, and it includes, for example, a hemispherical or parabola-shaped recess  40  formed at a central portion of its first principal surface  14   a.  The central housing member  70  has a rectangular contour, and it has a hollow section  72  having approximately the same diameter as the maximum diameter of the recess  40 . 
     In this embodiment, as shown in FIG. 19, the cavity  18  is formed by the recess  40  of the lower housing member  14 , the hollow section  72  of the central housing member  70 , and the first principal surface  12   a  of the upper housing member  12 . 
     Further, in the third modified embodiment, a light-reflective film  74 , which is made of, for example, aluminum, is formed, for example, by sputtering on the inner wall surface of the recess  40  of the lower housing member  14 . 
     Accordingly, in the display  10 Ac according to the third modified embodiment, the light components directed to the display surface of the housing  16 , of the light components radiated by the discharge light emission effected in the cavity  18  pass through the glass material having the light-transmissive property, and they outgo to the outside. However, the light components directed to the surfaces other than the display surface of the housing  16  are reflected by the light-reflective film  74 . As a result, almost all of the light components generated in the cavity  18  are directed to the display surface of the housing  16 . Thus, it is possible to achieve a higher brightness. Also in this embodiment, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities  18 . Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     In the display  10 Ac according to the third embodiment, it is preferable that the glass material having the light-transmissive property is used for the upper housing member  12 , and the glass material having no light-transmissive property is used for the central housing member  70 . As for the lower housing member  14 , the light-transmissive property of the glass material is irrelevant thereto, because the light-reflective film  74  is formed on the recess  40 . 
     A process for producing the display  10 Ac according to the third embodiment will now be explained with reference to FIG.  20 . 
     At first, the steps S 101  to S 103  are approximately the same as the steps S 1  to S 3  in the method for producing the display  10 A according to the first embodiment described above. In the step S 101 , various composition components are blended in order to obtain desired crystallized glass. In the next step S 102 , the blended preparation is heated and melted at a temperature of 1400° C. to 1500° C. Subsequently, in the step S 103 , the melted blended preparation is quenched and quickly cooled with water, oil or the like without causing crystallization in the same manner as in the ordinary glass production method. 
     In the step S 104 , the cooled blended preparation is processed to have a plate-shaped configuration to prepare three types of source plates, i.e., source plates for the upper housing member  12 , the central housing member  70 , and the lower housing member  14  respectively. 
     Subsequently, in the step S 105 , the source plates are press-formed to produce the plate-shaped upper housing member  12 , the central housing member  70  having the hollow section  72  in the axial direction, and the lower housing member  14  having the recess  40  at the central portion of the first principal surface  14   a.    
     Subsequently, in the step S 106 , the upper housing member  12  and the lower housing member  14 , which have been manufactured by the press forming as described above, are cooled, for example, to the room temperature. After that, in the step S 107 , the light-reflective film  74  is formed, for example, by means of the sputtering method on the inner wall surface of the recess  40  of the lower housing member  14 . 
     Subsequently, in the step S 108 , the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are wired and fixed, for example, on the contact surface of the central housing member  70  to make contact with the upper housing member  12 . 
     Subsequently, in the step S 109 , the upper housing member  12 , the central housing member  70 , and the lower housing member  14  are successively stacked, and they are thermally glued with each other by press under a pressure in a predetermined atmosphere, for example, in a xenon atmosphere at a high pressure (1 to 20 atms). Thus, the housing  16  is manufactured, which includes, at its inside, the cavity  18  formed by the first principal surface  12   a  of the upper housing member  12 , the hollow section  72  of the central housing member  70 , and the recess  40  of the lower housing member  14 . 
     Subsequently, in the step S 110 , the heat treatment is performed in order that the crystalline nucleuses are generated in the manufactured housing  16  to cause crystallization. Thus, the display  10 Ac according to the third modified embodiment is produced. 
     Next, a display  10 B according to the second embodiment will be explained with reference to FIGS. 21 to  27 . Components or parts corresponding to those shown in FIGS. 1 to  11  are designated by the same reference numerals, duplicate explanation of which will be omitted. 
     As shown in FIGS. 21 to  23 , the display  10 B according to the second embodiment is constructed in approximately the same manner as the display  10 A according to the first embodiment described above (see FIG.  1 ). However, the former is different from the latter in that the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are not constructed by the lead wires, but they are constructed by thin film patterns containing metal. Especially, in the second embodiment, in order to facilitate the connection to the vertical scanning circuit  32  and the horizontal scanning circuit  34  of the driving unit  30  (see FIG.  3 ), the respective thin film patterns for constructing the vertical selection line  24  and the signal line  26  are formed over the contact surface  14 a to the outer circumferential surface of the lower housing member  14 . 
     Further, as shown in FIG. 24, forward ends of the electrode wires  20 ,  22  based on the thin film pattern may be formed to have a sharp configuration. This arrangement is preferred in that the discharge efficiency is improved. 
     The method for forming the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film pattern on the contact surface  14   a  of the lower housing member  14  includes, for example, a method in which they are formed by printing a paste based on the use of a glass powder and a high melting point metal (for example, tungsten and molybdenum), and a method in which they are formed by using a sheet member comprising a metal foil formed on, for example, a film-shaped resin strip to stick the metal foil of the sheet member, for example, to the contact surface  14   a  of the lower housing member  14 , followed by peeling off the resin strip other than the metal foil. 
     As shown in FIG. 22, when the vertical selection line  24  and the signal line  26  are arranged and wired, the paste  28  made of glass material is formed at the portion of intersection between the vertical selection line  24  and the signal line  26  so that the vertical selection line  24  is insulated from the signal line  26 . 
     Also in the display  10 B according to the second embodiment, it is possible to simultaneously realize the integration and the miniaturization of the electronic tube, and it is possible to make the display expression for information transmission at a high brightness, in the same manner as in the display  10 A according to the first embodiment. 
     Especially, in the display  10 B according to the second embodiment, the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are constructed by using the thin film pattern. Therefore, the labor for the wiring arrangement is reduced, and it is possible to simplify the production steps, as compared with the case in which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are constructed by using the lead wires. Further, the positioning can be easily achieved in order that the electrode wires  20 ,  22  are opposed to one another with the cavity  18  interposed therebetween. 
     Next, a method for producing the display  10 B according to the second embodiment will be explained. This production method is carried out by executing approximately the same steps as those of the method for producing the display  10 A according to the first embodiment shown in FIG.  13 . However, the former is different from the latter in that the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are formed in the electrode formation in the step S 7  not by arranging the lead wire but by adopting, for example, the method based on the printing or the method based on the use of the sheet member as described above. 
     In this embodiment, it is possible to adopt, for example, a method in which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film are formed, for example, by means of printing by the aid of a paste  50  made of glass material applied to the contact surface  14   a  of the lower housing member  14  as shown in FIG. 25, a method in which a groove  52  for the thin film pattern is previously formed, for example, on the contact surface  14   a  of the lower housing member  14  so that the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film pattern are formed in the groove  52  as shown in FIG. 26, and a method in which the paste  50  made of glass material is applied to the groove  52  and then the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film pattern are formed as shown in FIG.  27 . 
     Next, several modified embodiments of the display  10 B according to the second embodiment will be explained with reference to FIGS. 28 to  31 . 
     At first, as shown in FIG. 28, a display  10 Ba according to a first modified embodiment comprises a recess  60  provided on the upper housing member  12  as well. In this embodiment, the cavity  18  is formed by the recess  60  of the upper housing member  12  and the recess  40  of the lower housing member  14 . 
     Next, as shown in FIG. 29, a display  10 Bb according to a second modified embodiment comprises a recess  60  provided on only the upper housing member  12 . In this embodiment, the cavity  18  is formed by the recess  60  and the first principal surface  14   a  of the lower housing member  14 . 
     Next, as shown in FIG. 30, a display  10 Bc according to a third modified embodiment is based on the display  10 Ba according to the first modified embodiment. However, the former is different from the latter in that a tapered surface  40   a  is formed at the circumferential edge of the recess  40  of the housing member (the lower housing member  14  in the illustrated embodiment) on which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film pattern are not formed, of the upper housing member  12  and the lower housing member  14 . 
     In this embodiment, it is possible to avoid the inconvenience which would otherwise occur such that the glass component of the lower housing member  14  covers the forward ends of the electrode wires  20 ,  22  constructed by the thin film pattern, during the discharge light emission. Thus, it is possible to contemplate the reliability of the discharge light emission. 
     Next, as shown in FIG. 31, a display  10 Bd according to a fourth modified embodiment comprises three stacked housing members. The upper housing member  12  is formed to have a rectangular plate-shaped configuration. The lower housing member  14  has a rectangular contour, and it includes, for example, a hemispherical or parabola-shaped recess  40  formed at a central portion of its first principal surface  14   a.  The central housing member  70  has a rectangular contour, and it has a hollow section  72  having approximately the same diameter as the maximum diameter of the recess  40 . 
     In this embodiment, the cavity  18  is formed by the recess  40  of the lower housing member  14 , the hollow section  72  of the central housing member  70 , and the first principal surface  12   a  of the upper housing member  12 . 
     Further, in the fourth modified embodiment, a light-reflective film  74 , which is made of, for example, aluminum, is formed, for example, by sputtering on the inner wall surface of the recess  40  of the lower housing member  14 . 
     In the display  10 Bd according to the fourth modified embodiment, almost all of the light components generated in the cavity  18  are directed to the display surface of the housing  16 . Thus, it is possible to achieve a higher brightness. Further, it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities  18 . Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     Also in this embodiment, it is preferable that the glass material having the light-transmissive property is used for the upper housing member  12 , and the glass material having no light-transmissive property is used for the central housing member  70 . 
     When the display  10 Bd according to the fourth modified embodiment is produced, approximately the same steps are executed as those of the production method of the third modified embodiment of the display  10 A according to the first embodiment shown in FIG.  20 . However, the production method differs in that the wiring arrangement based on the lead wire is not used in the electrode formation in the step S 108 , but the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  based on the thin film pattern are formed, for example, by the method based on the printing or the method based on the use of the sheet member described above. The common features have been described in detail in the description of the method for producing the display  10 B according to the second embodiment, detailed explanation of which will be omitted in this section. 
     The crosstalk of light emission between the cavities  18  is effectively avoided in the displays  10 A,  10 B according to the first and second embodiments described above such that the lower housing member  14  of the housing members  12 ,  14  for constructing the housing  16 , which does not contribute to the display expression, is constructed by using the glass material having no light-transmissive property. The crosstalk of light emission between the cavities  18  is effectively avoided in the third modified embodiment (display  10 Ac) of the display  10 A according to the first embodiment and the fourth modified embodiment (display  10 Bd) of the display  10 B according to the second embodiment such that the light-reflective film  74  is formed on the inner wall surface of the recess  40  of the lower housing member  14 . Besides, the prevention of crosstalk can be also achieved by using arrangements shown in FIGS. 32 to  34 . 
     That is, a display  10 C according to the third embodiment shown in FIG. 32 comprises, for example, V-shaped grooves  100  which are formed, for example, by means of press forming so that they extend from the lower surface of the lower housing member  14  between the cavities  18  of the lower housing member  14 . A light-shielding substance  102  is charged in the grooves  100 . 
     A display  10 D according to the fourth embodiment shown in FIG. 33 comprises, in addition to the arrangement shown in FIG. 32, V-shaped grooves  104  which are formed, for example, by means of press forming so that they extend from the upper surface of the upper housing member  12  at positions in the upper housing member  12  corresponding to the intervals between the cavities  18  as well. A light-shielding substance  106  is charged in the grooves  104 . 
     A display  10 E according to the fifth embodiment shown in FIG. 34 is arranged as follows. That is, for example, rectangular grooves  110 ,  112  are previously formed, for example, by press forming at positions between the cavities  18  respectively, of the respective confronting surfaces of the upper housing member  12  and the lower housing member  14 . When the upper housing member  12  and the lower housing member  14  are thermally glued under a pressure thereafter, a light-shielding substance  114  is charged in a hollow section which is formed by the grooves  110 ,  112 . 
     Also in the arrangements shown in FIGS. 32 to  34 , it is possible to effectively avoid the crosstalk of light emission, which would be otherwise caused between the cavities  18 . Thus, it is possible to effectively avoid the phenomenon which would otherwise result in the deterioration of image quality such as the image disturbance and the afterimage phenomenon. 
     Next, the color display will be explained concerning the display  10 A according to the first embodiment and the display  10 B according to the second embodiment. Several representative cases will be explained, in which the color display is applied to the display  10 B according to the second embodiment. 
     As shown in FIG. 35, a first example for the color display resides in a method in which, for example, color filters  80 R,  80 G,  80 B of R (red), G (green), B (blue) are formed in the unit of three picture elements at positions corresponding to the cavities  18  respectively on the second principal surface (display surface) of the upper housing member  12  which constitutes the housing  16 . 
     As shown in FIG. 36, a second example for the color display resides in a method in which a means  82  for selecting the light component such as an optical switch and an optical shutter is provided on the side of the second principal surface (display surface) of the upper housing member  12  which constitutes the housing  16 . 
     The xenon gas, which is enclosed in the large number of cavities  18  in the housing  16 , has the distinct line spectrum in the infrared region (at a wavelength of about 800 μ). However, the xenon gas exhibits the continuous spectrum in the visible light region, and it has the light components of R, G, B. 
     It is now assumed that the cycle for emitting light by the aid of the selecting means  82  for the light component is T, and the maximum light emission time for RGB is divided into three. As shown in FIG. 37A, when the ratio of light emission time for RGB is 1:1:1, the white light is obtained. As shown in FIG. 37B, when the ratio of light emission time for RGB is 4:1:5, a neutral color corresponding to the ratio is obtained. Therefore, the time of light emission may be controlled as follows. That is, the light emission time in the cavity  18  is synchronized with the cycle T for light emission so that the light emission time for the three primary colors may be controlled. Alternatively, the light emission time for the three primary colors is synchronized with the cycle T for light emission so that the light emission time in the cavity  18  may be controlled. 
     The second example is advantageous in that it is unnecessary to increase the number of picture elements as compared with the black-and-white screen even in the case of application to the color display system. 
     In the displays  10 A,  10 B according to the first and second embodiments described above, the cavities  18  of the number corresponding to the number of picture elements are formed in one housing  16 . Alternatively, another arrangement is available as shown in FIG.  38 . That is, housings  16  are manufactured, each of which includes only one cavity  18  formed at the inside. The housings  16  are arranged in a number corresponding to the number of picture elements, and they are secured with each other by using, for example, a light-transmissive adhesive to construct one display  10 F (conveniently referred to as the “display  10 F according to the sixth embodiment”). FIG. 38 is illustrative of a case in which the vertical selection line  24 , the signal line  26 , and the electrode wires  20 ,  22  are formed by using the thin film pattern in the same manner as in the display  10 B according to the second embodiment. 
     When the color display is applied to the display  10 F according to the sixth embodiment, it is also preferable to adopt the first example (color filter) and the second example (use of the optical switch or the optical shutter) described above. 
     Alternatively, three types of housings may be prepared, i.e., the housing  16  in which a red coloring agent (for example, Se and sodium gold chloride) is added to the upper housing member  12 , the housing  16  in which a green coloring agent (for example, Cr) is added to the upper housing member  12 , and the housing  16  in which a blue coloring agent (for example, Co) is added to the upper housing member  12 . The three types of housings  16  may be arranged so that they are optimized for the color display. In other words, a method is provided, in which the upper housing members  12  themselves are used as color filters. 
     In the displays  10 A to  10 F according to the first to sixth embodiments described above (including the displays concerning the various modified embodiments), the upper housing member  12  and the lower housing member  14 , each of which has the plate-shaped configuration, are joined to one another by means of the thermal adhesion by press under the pressure to produce the plate-shaped housing  16 . Alternatively, hemispherical housing members may be joined to produce a spherical housing. The shape of the housing  16  is not especially limited. The xenon gas is used as the gas to be enclosed in the cavity  18  of the housing  16 . Alternatively, it is possible to use other gases such as mercury and argon. 
     It is a matter of course that the display and the method for producing the same according to the present invention are not limited to the embodiments described above, which may be embodied in other various forms without deviating from the gist or essential characteristics of the present invention. 
     As explained above, according to the display concerning the present invention, it is possible to simultaneously realize the integration and the miniaturization of the electronic tube and present the display expression for information transmission at a high brightness. 
     According to the method for producing the display concerning the present invention, it is possible to easily produce the display which makes it possible to simultaneously realize the integration and the miniaturization of the electronic tube and present the display expression for information transmission at a high brightness.