Abstract:
A display apparatus having a first plate-shaped member having plural electron-emitting devices which are dispersively distributed and a second plate-shaped member having a plurality of light-emitting members arranged on a surface which faces the first plate-shaped member in correspondence to the plural electron-emitting devices, in which in at least either the first plate-shaped member or the second plate-shaped member, directions of normal lines extending from the plural electron-emitting devices or the plural light-emitting members are distributed in a tendency. A pitch of arranging the adjacent electron-emitting devices and a pitch of arranging the light-emitting members corresponding to the adjacent electron-emitting devices are different in accordance with the distribution of the normal-line directions.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to an image display apparatus using electron-emitting devices.  
         [0003]     2. Related Background Art  
         [0004]     Flat panel type image display apparatuses have been vigorously being studied and developed as display apparatuses of images, characters, and the like. A large panel display screen size and high definition are demanded for the flat panel type-image display apparatuses.  
         [0005]     In a PDP, an LCD, and an SED (surface conduction type electron-emitting device display) as flat panel type image display apparatuses, flat panel glass is used and a thickness of image display apparatus lies within a range from a few cm to tens of cm and is thinner than general CRTs. Although those display apparatuses are of the flat panel type, actually they have a warp of about a few mm or less which is caused due to a manufacturing processor the like. There is a case where a color variation and a luminance variation are caused by such a warp.  
         [0006]     The image display apparatus in which such a warp occurred has been disclosed in for example, JP-A-2003-109528 and is shown in  FIG. 13 .  
         [0007]      FIG. 13  is a schematic cross sectional view of a panel main body using electron-emitting devices. A frame-shaped supporting spacer  40  is interposed between a face plate  30  and a rear plate  20  in which a number of electron-emitting devices  10  are arranged in a matrix shape on one surface side. A space formed by those plates  20  and  30  and the spacer  40  is held in a vacuum state. A collector electrode made of an ITO film is formed on the surface of the face plate  30  which faces the rear plate  20 . Each electron-emitting device  10  is arranged every sub-pixel  32  consisting of one phosphor cell (phosphor layer). Each sub-pixel  32  is excited by an electron beam which is irradiated from the electron-emitting device  10  and emits light to a color region of one of the three primary colors of R, G, and B. As shown in the diagram, the face plate  30  has a curved shape which is convex to an outer surface side.  
         [0008]     As for the sub-pixels  32  provided for the face plate  30 , a pitch between the sub-pixels  32  is set so that sizes of projection images onto the one surface of the rear plate  20  in the sub-pixels  32  are made coincident. Therefore, the projection image of the sub-pixel  32  is almost equal to the surface shape of the electron-emitting device  10  and is overlapped to the electron-emitting device  10 . Consequently, it is possible to prevent the electron emitted from the adjacent electron-emitting device  10  from reaching, a blur of an image can be prevented, and color reproducibility can be improved.  
         [0009]      FIG. 1  is a schematic cross sectional view schematically showing a structure of a panel which is used in the flat panel type image display apparatus. Reference numeral  101  denotes a rear plate;  102  a face plate;  103  a frame; and  104  a panel obtained by sealing and bonding the rear plate  101 , face plate  102 , and frame  103  by a panel sealing step. The inside of the panel  104  is held in a vacuum state. Reference numeral  105  denotes an electron source pattern formed on the surface of the rear plate  101  which faces the face plate  102 . The electron source pattern  105  is formed by a plurality of electron-emitting devices. Reference numeral  106  denotes a phosphor pattern formed on the surface of the face plate  102  which faces the rear plate  101 . The phosphor pattern  106  is formed by a plurality of phosphor (light-emitting members) and each phosphor corresponds to each electron-emitting device.  
         [0010]     There is a case where a temperature difference or the like occurs between the rear plate  101  and the faceplate  102  in a thermal process in the panel sealing step. Thus, there is a case where the rear plate  101  and the face plate  102  which were almost flat surfaces before the panel sealing step are warped after that, so that the panel  104  is warped as illustrated in  FIG. 1 .  
         [0011]     There is also a case where the fear plate  101  or the face plate  102  is sealed and bonded in the panel sealing step by using a hot plate while being pressed, or the like. In the hot plate, there is a case where a slight warp is caused by a thermal distortion and the hot plate becomes a non-flat surface after the sealing step is repetitively executed.  
         [0012]     In the panel in which such a temperature difference occurs or the panel which was sealed and bonded by the warped hot plate, a warp occurs and the panel becomes the non-flat surface. Such a warp becomes remarkable with an increase in panel size.  
         [0013]     In the flat panel type display apparatus, there is a case where a spacer is interposed between the face plate and the rear plate so that a space between the rear plate  101  and the face plate  102  is not broken by the atmospheric pressure. In the case of such a construction, since the rear plate  101  and the face plate  102  are pressed to the spacer by the atmospheric pressure, a macroscopic radius of curvature of the whole rear plate  101  and that of the whole face plate  102  almost coincide.  
         [0014]     It is now presumed the panel  104  in which the electron source pattern  105  and the phosphor pattern  106  are formed at the same size on the rear plate  101  and the face plate  102  in the almost flat surface state, respectively, and the panel  104  is sealed and bonded so that a center position of the rear plate  101  and that of the face plate  102  coincide. An electron beam emitted from the electron-emitting device is irradiated in the direction of a normal line of the rear plate in the electron-emitting device. Therefore, if the panel is warped by the foregoing reasons, a difference of δ/2 occurs in each of both ends as shown in  FIG. 1 .  
         [0015]     In other words, a position of a center of gravity of phosphor which should inherently exist does not exist in the direction of a normal line of a position of a center of gravity of a certain electron-emitting device or apposition of a center of gravity of the emitted electron beam, so that a deviation occurs in an irradiating position of the electron beam to the face plate. Such a situation is illustrated in  FIG. 14 .  
         [0016]     When the electron beam is deflected by a deflecting voltage or the like, an ideal position of the center of gravity of phosphor is set in consideration of its deflection amount and a similar idea is used.  
         [0017]     Although such a positional deviation due to the warp is small at the center of a display screen, it increases as a position approaches an outer position of the display screen. When the positional deviation is small, there is no problem as picture quality.  
         [0018]     However, as the positional deviation amount increases, the electron beam is deviated from phosphor to be inherently irradiated by the electron beam, so that luminance decreases. Further, when the positional deviation increases, phosphor adjacent to phosphor to be inherently irradiated by the electron beam is irradiated, so that a color drift occurs in the case of a color television. Such a color drift becomes a typical problem with an increase in size of display screen.  
         [0019]     The decrease in the luminance can be suppressed to a certain extent by increasing a size of phosphor to a value larger than abeam size. However, in the case of a high-definition display apparatus, the positional deviation becomes a remarkable problem.  
         [0020]     As mentioned above, the positional deviation which is caused by the warp of the airtight container (panel) will become an important problem in association with the realization of a large screen size and high definition of the image display apparatus in the future.  
       SUMMARY OF THE INVENTION  
       [0021]     According to the invention which solves the above problems, there is provided a display apparatus comprising  
         [0022]     a first plate-shaped member having a plurality of electron-emitting devices which are dispersively distributed and  
         [0023]     a second plate-shaped member having a plurality of light-emitting members arranged on a surface which faces the first plate-shaped member in correspondence to the plurality of electron-emitting devices,  
         [0024]     in which in at least either the first plate-shaped member or the second plate-shaped member, directions of normal lines extending from the plurality of electron-emitting devices or the plurality of light-emitting members are distributed in a tendency,  
         [0025]     wherein a pitch between at least a part of the electron-emitting devices and an electron-emitting device adjacent to the electron-emitting device and a pitch between a light-emitting member corresponding to the electron-emitting device and a light-emitting member adjacent to the light-emitting member are different so that an electron emitted from each of the plurality of electron-emitting devices is irradiated to each of the plurality of corresponding light-emitting members. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a schematic cross sectional view schematically showing a structure of a panel;  
         [0027]      FIG. 2  is a schematic cross sectional view schematically showing a structure of a panel;  
         [0028]      FIG. 3  shows a state before a sealing step;  
         [0029]      FIG. 4  is a schematic cross sectional view of a panel  104  obtained after the sealing step;  
         [0030]      FIG. 5  is a diagram for explaining a phosphor pattern;  
         [0031]      FIG. 6  is a diagram for explaining an electron source pattern;  
         [0032]      FIG. 7  is a schematic perspective view for explaining the first embodiment;  
         [0033]      FIG. 8  is a schematic perspective view for explaining the second embodiment;  
         [0034]      FIG. 9  is a schematic cross sectional view of a panel  204 ;  
         [0035]      FIG. 10  is a schematic perspective view for explaining the third embodiment;  
         [0036]      FIG. 11  shows a phosphor pattern  308  which is formed on a face plate;  
         [0037]      FIG. 12  shows an electron source pattern  307  which is formed on a rear plate;  
         [0038]      FIG. 13  shows a prior art;  
         [0039]      FIG. 14  is a partial enlarged diagram for explaining the problem; and  
         [0040]      FIG. 15  is a partial enlarged diagram of an image display apparatus to which the invention is applied. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]      FIG. 2  is a schematic cross sectional view schematically showing a structure of a panel of the invention. Reference numeral  101  denotes the rear plate;  102  the face plate;  103  the frame; and  104  the panel obtained by sealing and bonding the rear plate  101 ′, face plate  102 , and frame  103  by the panel sealing step. The panel  104 ′ has a non-flat shape in which the surface of the face plate  102  side is convex. The frame  103  is fixed by a sealing material (not shown) having a sealing function to keep a vacuum hermetical state. The inside of the panel  104  is held in a vacuum state. Reference numeral  107  denotes an electron source pattern formed on the surface of the rear plate  101  which faces the face plate  102 . The electron source pattern  107  is formed by a plurality of electron-emitting devices. Reference numeral  108  denotes a phosphor pattern formed on the surface of the face plate  102  which faces the rear plate  101 . The phosphor pattern  108  is formed by a plurality of phosphor (light-emitting members) and each phosphor corresponds to each electron emitting device. By forming the phosphor pattern  108  so as to be longer (larger) than the electron source pattern  107 , the occurrence of the relative positional deviation between the patterns can be prevented in the state of the warped panel  104 .  
         [0042]     The following two methods of causing a difference between the relative pattern sizes can be mentioned.  
         [0043]     (1) A size of phosphor pattern is used as a reference and a size of electron source pattern is changed.  
         [0044]     (2) The size of electron source pattern is used as a reference and the size of phosphor pattern is changed.  
         [0045]     The size of phosphor pattern denotes a distance between both ends of the phosphor pattern. The size of electron source pattern denotes a distance between both ends of the electron source.  
         [0046]     Since an image is determined by the phosphor pattern, the method (1) is preferable. However, if the method (1) is difficult to be used depending on a manufacturing process or the like, the method (2) can be also used.  
         [0047]     The following two methods of changing the size of pattern can be mentioned.  
         [0048]     (3) A phosphor pitch (pitch of arranging the light-emitting members) and an electron-emitting device pitch (pitch of arranging the electron emitting devices) are made different without changing one phosphor size or one electron-emitting device size.  
         [0049]     (4) The phosphor pitch and the electron-emitting device pitch are equalized and one phosphor size or one electron-emitting device size is made different.  
         [0050]     Even by changing the phosphor size and the electron source size, if no change appears in the luminance, the method (4) may be used. However, if a change occurs in the luminance, the method (3) is properly used.  
         [0051]     To realize high definition or increase a relative positioning margin of the rear plate  101  and the face plate  102  in the sealing step, it is desirable to select the methods (1) and (3).  
         [0052]     Subsequently, the difference of the pattern sizes is quantitatively-calculated from the warped shape of the panel  104 .  FIG. 3  shows the state before the sealing step.  FIG. 4  shows a schematic cross sectional view of the panel.  
         [0053]     In  FIG. 3 , reference numeral  113  denotes a neutral plane of the rear plate  101 ;  114  a neutral plane of the face plate  102 ;  119  a point A′; and  120  a point B′. The points A′ and B′ are both ends of the electron source pattern  107 . Reference numeral  115  denotes a point A and  116  indicates a point B. The points A and B are points obtained by projecting the points A′  119  and B′  120  to the neutral plane  113  of the rear plate. When a distance between the points A and B is assumed to be L−δ, a distance between the points A′ and B′ is also equal to L−δ. The neutral plane denotes a virtual plane locating at a center portion in the depth direction of each member.  
         [0054]     Reference numeral  121  denotes a point C′ and  122  indicates a point D′. The points C′ and D′ are both ends of the phosphor pattern  108 . Reference numeral  117  denotes a point C and  118  indicates a point D. The points C and D are points obtained by projecting the points C′  121  and D′  122  to the neutral plane  114  of the face plate. When a distance between the points C and D is assumed to be L, a distance between the points C′ and C′ is also equal to L. That is, the phosphor pattern  108  is formed so as to be longer (larger) than the electron source pattern  107  by δ.  
         [0055]      FIG. 4  is a schematic cross sectional view of the panel  104  obtained after the sealing step. Reference numeral  112  denotes a neutral plane of the panel  104 . The panel  104  is warped by a warp amount h in a region where an image is displayed (almost the same region as the phosphor pattern  108 ). The neutral plane  112  of the panel  104  is warped at a radius of curvature R. This radius of curvature is assumed to be a representative radius of curvature. The representative radius of curvature is equal to or larger than tens of meter. Therefore, when a distance between the rear plate and the face plate is equal to about a few millimeter and a thickness of each of the face plate and the rear plate is equal to about a few millimeter, a radius of curvature of each of the rear plate  101  and the face plate  102  is almost equal to the representative radius of curvature.  
         [0056]     Since a length of neutral plane of the rear plate  101  and a length of neutral plane of the face plate  102  are almost equal, an arc AB=L−δ and an arc CD=L. However, since the rear plate  101  and the face plate  102  are warped, it is necessary to form them so that the electron-emitting device pitch and the phosphor pitch are made different. This point is expressed by the following equations.  
               Arc   ⁢           ⁢     A   ′     ⁢     B   ′       =     arc   ⁢           ⁢   AB   ×     [     1   +       T   1     /     (     2   ⁢   R     )         ]                   =       (     L   -   δ     )     ×     [     1   +       T   1     /     (     2   ⁢   R     )         ]                 
               Arc   ⁢           ⁢     C   ′     ⁢     D   ′       =     arc   ⁢           ⁢   CD   ×     [     1   -       T   2     /     (     2   ⁢   R     )         ]                   =     L   ×     [     1   -       T   2     /     (     2   ⁢   R     )         ]                 
 
 where, 
 
         [0057]     T 1 : thickness of rear plate  101   
         [0058]     T 2 : thickness of face plate  102   
         [0059]     To eliminate the positional deviation, it is necessary that a point O and the points A′ and C′ are aligned on a straight line and, at the same time, the point  6  and the points B′ and D′ are aligned on a straight line. Assuming that a distance between the rear plate  101  and the face plate  102  is equal to S, it is preferable that the following equation is satisfied. 
 
Arc  C′D′ =arc  A′B′×[ 1 +S /(2 R )]
 
         [0060]     The above calculations are executed. For simplicity of the calculations, it is assumed that each of T 1 , T 2 , and S is equal to about a few millimeter, δ is equal to or less than 1 mm, L is equal to about 1 m, and R is equal to about tens of meter and the term whose value is very small is ignored. Thus, the following result which is substantially correct is obtained. 
 
δ= L [( T   1   +T   2 )/2 +S]/R  
 
 where, [(T 1 +T 2 )/2+S] coincides with the distance between the neutral plane  113  of the rear plate  101  and the neutral plane  114  of the face plate  102 . That is, assuming that the distance between the neutral plane  113  of the rear plate  101  and the neutral plane  114  of the face plate  102  is set to T, 
 
δ= TL/R  
 
         [0061]     Further, there is a relation of the following equation between the warp amount h and the radius of curvature. 
 
 R=L   2 /8 h  
 
         [0062]     The following equation is obtained by using the above equation. 
 
δ=8 Th/L  
 
         [0063]     That is, it is sufficient to set the size of electron source pattern  107  to be smaller than the size of phosphor pattern  108  by δ. When expressing it in a manner of a reduced scale, it is sufficient to set the size of electron source pattern  107  to be K times as large as the size of phosphor pattern  108 .  
         [0064]     K=(L−δ)/L=(L−TL/R)/L=1−T/R  
         [0065]     The phosphor pattern and the electron source pattern-shown in  FIGS. 5 and 6  will now be described. In  FIG. 5 , reference numeral  123  denotes phosphor. In the cross sectional view, the phosphor pattern  108  is constructed by N phosphor (light-emitting members)  123 . The light-emitting members are arranged at an equal pitch and assuming that the pitch is equal to P, a size L of phosphor pattern is defined by the following equation. 
 
 L=N×P  
 
         [0066]     In  FIG. 6 , reference numeral  124  denotes electron-emitting devices. The electron source pattern  107  is constructed by the N electron-emitting devices  124 . The electron-emitting devices are arranged at an equal pitch and this pitch is assumed, to be p, the size L−δ of the electron source pattern is expressed by the following equation. 
 
 L−δ=N×p  
 
         [0067]     Thus, it is sufficient to set p as follows.  
         [0068]     p=P−δ/N=P−TL/NR  
         [0069]      FIG. 15  shows a partial enlarged diagram of an image display apparatus to which the invention is applied.  
         [0070]     T denotes the distance between the neutral plane  113  of the rear plate  101  and the neutral plane  114  of the face plate  102 . Therefore, the larger the substrate thickness of the rear plate  101  or the face  10  plate  102  is, the larger a value of T is. The larger the distance between the rear plate  101  and the face plate  102  is, the larger the value of T is. Consequently, in the FED type image display apparatus in which the distance between the rear plate  101  and the face plate  102  needs to be set to a value within a range of about 0.5 to 3 mm or more, the positional deviation due to the warp is large and the invention is very effective.  
         [0071]     The larger the panel size is, the higher definition in the panel sealing process or the like is necessary and the more the warp amount increases.  
         [0072]     Therefore, a value of h/L increases with an increase in panel size L. Thus, the larger the panel size is, the more the invention becomes effective.  
         [0073]     In the above embodiment, the flat panel type image display apparatus using the surface conduction type electron-emitting devices as an electron source has been shown. However, the invention is not limited to such an apparatus. A similar effect is also obtained in a flat panel type image display apparatus using field emission type electron-emitting devices or the like as an electron source, a PDP, or the like.  
       EMBODIMENTS  
     First Embodiment  
       [0074]      FIG. 3  is a diagram for explaining the first embodiment. The rear plate  101  is a glass substrate having a thickness of T 1 =2.8 mm. The face plate  102  is a glass substrate having a thickness of T 2 =2.8 mm. The panel  104  shown in  FIG. 7  is formed by sealing the rear plate  101 , face plate  102 , and frame  103  by using a sealing material (not shown) by the sealing process. The panel  104  is warped in a convex shape in the direction directing from the rear plate  101  to the face plate  102  and has an almost circular shape. In the panel  104 , the distance between the rear plate  101  and the face plate  102  is equal to 2 mm.  
         [0075]     In  FIG. 7 , reference numeral  125  denotes a cross sectional plane E to observe a cross sectional structure of the panel  104 .  FIG. 4  shows a cross sectional schematic diagram of the panel  104  cut at the plane E  125 . It has previously been known that the warp amount h of 1 mm occurs due to the sealing process, mainly, by heating temperature characteristics of a sealing apparatus. A radius of curvature in this case is equal to about 77 m.  
         [0076]     The length L of phosphor pattern  108  is equal to 787.2 mm. The electron source pattern  107  has to be formed so as to be smaller than the length of phosphor pattern by δ in consideration of the positional deviation due to the warp. The electron source is constructed by a plurality of surface conduction type electron-emitting devices. When δ is calculated, it is equal to 49 μm. Therefore, the electron source pattern  107  is formed so that its length is equal to 787.151 mm. The phosphor pitch P is set to 205 μm. Therefore, when the panel is sealed and bonded so that the positional deviation does not occur at the center of the phosphor pattern  108 , a positional deviation of 24.5 μm occurs at both ends of the phosphor pattern  108 . Non-light emitting regions each having a width of 30 μm and called a black matrix are formed among a plurality of light-emitting members although not shown. Therefore, in the display apparatus which does not use the invention, a bombarding position of the electron beam is deviated, the electron beam is bombarded to the non-light emitting region, and the luminance decreases. However, the good image can be obtained by taking the countermeasure of the invention.  
       Second Embodiment  
       [0077]      FIG. 8  is a diagram for explaining the second embodiment. A rear plate  201  is a glass substrate having a thickness of T 1 =2.8 mm. A face plate  202  is a glass substrate having a thickness of T 2 =2.8 mm. A panel  204  shown in  FIG. 8  is formed by sealing the rear plate  201 , face plate  202 , and frame  203  by using the sealing material (not shown) by the sealing process. The panel  204  is warped in a convex shape in the direction directing from the rear plate  201  to the face plate  202  and is in a non-flat surface state. In the panel  204 , a distance between the rear plate  201  and the face plate  202  is equal to 1.6 mm.  
         [0078]     In  FIG. 8 , reference numeral  225  denotes a cross sectional plane F to observe a cross sectional structure of the panel  204 .  FIG. 9  shows a cross sectional schematic diagram of the panel  204  cut at the plane F  225 . The panel  204  has a non-flat surface shape due to the sealing process and its states in three zones are different. In terms of this point, such a shape has been presumed by the sealing process, mainly, by the heating temperature characteristics of the sealing apparatus. In a zone  1 , there is no warp in the panel shape and the rear plate  201  and the face plate  202  are almost flat surfaces. In a zone  2 , the panel shape is a cylindrical shape having a radius of curvature R 2  while a point O 1    205  is set to the center. In a zone  3 , although the panel shape is a cylindrical shape, its radius of curvature differs from that in the zone  2 , that is the panel shape is the cylindrical shape having a radius of curvature R 3  while a point O 2    206  is set to the center. By measuring the shapes of the panels and the like, it has been found that R 2 =100 m and R 3 =60 m. The zones  1 ,  2 , and  3  are obtained by dividing a phosphor pattern  208  into almost three equal regions.  
         [0079]     In the zone  1 , since there is no radius of curvature, when the positional deviation due to the warp occurs, the positional deviation amounts are equal in the zone  1 .  
         [0080]     Since the panel shape as mentioned above has previously been known by the heating temperature characteristics of the sealing apparatus, the pattern which eliminates the positional deviation is prepared.  
         [0081]     A length of phosphor pattern  208  is set to L=787.2 mm. On the other hand, in order to decide a length of electron source pattern  207 , δ 1 , δ 2 , and δ 3  in the zones  1 ,  2 , and  3  are obtained.  
         [0082]     δ 1 =0 mm. δ 2 =11.5 μm when the radius of curvature of 100 m is used for the length of about 262 mm. δ 3 =19.2 μm when the radius of curvature of 60 m is used for the length of about 262 mm.  
         [0083]     The electron source pattern is constructed by 7680 electron-emitting devices (not shown). In  FIG. 9 , 2566 electron-emitting devices are included in the zone  1 , 2560 electron-emitting devices are included in the zone  2 , and 2560 electron-emitting devices are included in the zone  3 . The panel is sealed and bonded so that the relative positional deviation does not occur in the center electron-emitting device and phosphor of the zone  2 , that is, in the 3840th electron-emitting device from the edge and phosphor. The electron source pattern including the 3840 electron-emitting devices of the zone  2  is, manufactured so as to have a length of 262.3885 mm which is smaller than the phosphor pattern (262.4 mm) by 11.5 μm. The electron source pattern including the 3840 electron sources of the zone  1  is manufactured so as to have the same length of 262.4 mm as that of phosphor pattern (262.4 mm) in the state where it is connected to the left side of the zone  2  in the diagram. The electron source pattern including the 3840 electron sources of the zone  3  is manufactured so as to have a length of 262.3808 m=which is smaller than the phosphor pattern (262.4 mm) by 19.2 μm in the state where it is connected to the right side of the zone  2  in the diagram.  
         [0084]     That is, the positional deviation can be eliminated by allocating the electron source pattern  207  having three pattern pitches of the zones  1 ,  2 , and  3  to the phosphor pattern  208  having a predetermined pattern pitch.  
         [0085]     Finally, it is sufficient to form the electron source pattern  207  so as to be smaller than the phosphor pattern by 31 μm. Therefore, the length of electron source pattern  207  is equal to 787.169 mm.  
         [0086]     The electron-emitting devices are the surface conduction electron-emitting devices.  
         [0087]     The phosphor pitch is set to 102.5 μm. When the same electron source pattern as the phosphor pattern is used without considering the positional deviation, if the panel is sealed and bonded so that no positional deviation occurs at the center of the phosphor pattern  208 , the positional deviation of 15.5 μm has occurred at each of both ends of the phosphor pattern  208 . The non-light emitting regions (not shown) each having a width of 12 μm and called a black matrix are formed among a plurality of light-emitting members. Therefore, in the display apparatus which does not use the invention a bombarding position of the electron beam is deviated, the electron beam is bombarded to the adjacent light-emitting member, and the decrease in luminance and the color drift occur. However, the good image can be obtained by taking the countermeasure of the invention.  
       Third Embodiment  
       [0088]      FIG. 10  is a diagram for explaining the third embodiment. A rear plate  301  is a glass substrate having a thickness of T 1 =1.8 mm. A face plate  302  is a glass substrate having a thickness of T 2 =1.8 mm. A panel  304  is formed by sealing the rear plate  301 , face plate  302 , and frame  303  by using the sealing material (not shown) by the sealing process. The panel  304  is warped in a convex shape in the direction directing from the face plate  302  to the rear plate  301 . In the panel  304 , a distance between the rear plate  301  and the face plate  302  is equal to 2 mm.  
         [0089]     By measuring a 3-dimensional shape, it has been found that the panel has an almost spherical shape whose radius of curvature is equal to about 85 m (R=85 m). Such a shape has been presumed by the sealing process, mainly, by the heating temperature characteristics of the sealing apparatus.  
         [0090]     Since the panel has the convex shape in the direction directing from the face plate  302  to the rear plate  301 , an electron source pattern which is formed on the rear plate  301  has to be larger than a phosphor pattern which is formed on the face plate  302 .  
         [0091]      FIG. 11  shows a phosphor pattern  308  which is formed on the face plate.  FIG. 12  shows an electron source pattern  307  which is formed on the rear plate. The phosphor pattern  308  is formed by a plurality of phosphor (light-emitting members)  323 . The electron source pattern  307  is formed by a plurality of electron-emitting devices  324 . As a size of phosphor pattern, a length in the X direction (longitudinal direction) is assumed to be Lx and a length in the Y direction (short-side direction) is assumed to be Ly. It is sufficient that the length in the X direction of the electron source pattern  307  is set to be larger than Lx by δx, that is, (Lx+δx) in order to correct the positional deviation due to the warp and the length in the Y direction of the electron source pattern  307  is set to be larger than Ly by δy, that is, (Ly+δx).  
         [0092]     According to the above examination, Lx is equal to 985.9 mm, an X-directional pitch Px of the electron-emitting devices  324  is equal to 0.514 mm, Ly is equal to 554.6 mm, a Y-directional pitch Py of the electron-emitting devices  324  is equal to 0.514 mm. Thus, δx=41.8 μm and δy=23.5 μm.  
         [0093]     Therefore, the electron source pattern  307  is not made coincident with the phosphor pattern  308  but the length Lx in the X direction is set to 985.942 mm which is larger by 41.8 μm and the length Ly in the Y direction is set to 554.624 mm which is larger by 23.5 μm.  
         [0094]     The electron-emitting devices are the surface conduction electron-emitting devices.  
         [0095]     When the image is displayed onto the panel, the good image without decrease in luminance can be obtained.  
         [0096]     Although the invention has been described above with respect to the embodiments, the invention is not limited to them. For example, as for the convex shape in each embodiment, when the convex shape directing from the rear plate to the face plate is changed to the convex shape directing from the face plate to the rear plate, it can be realized by replacing the relation between the electron-emitting device pitch and the phosphor pitch. Similarly, when the convex shape directing from the face plate to the rear plate is changed to the convex shape directing from the rear plate to the face plate, it can be realized by replacing the relation between the electron-emitting device pitch and the phosphor pitch.  
         [0097]     As described above, according to the invention, by changing the sizes of the phosphor pattern and the rear plate pattern or by changing the pattern pitch, the relative positional deviation due to the warp is eliminated and the image forming apparatus without the luminance variation and the color drift can be manufactured.  
         [0098]     This application claims priority from Japanese Patent Application No. 2004-379827filed on Dec. 28, 2004, which is hereby incorporated by reference herein.