JP2004193024A - Glass panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass panel capable of clearly displaying an image. <P>SOLUTION: A glass panel 101 which is provided to a PDP100 comprises a front plate glass 102 of thickness, for example, 2.8mm, and a back plate glass 104 of thickness, for example, 2.8mm which is arranged away from the front plate glass 102 by, for example, 0.1mm to form a hollow part 103 with the front plate glass 102. The front plate glass 102 is sealed with the back plate glass 104 with a sealing part 105 comprising a low melting point glass paste at an outer peripheral edge so that a rare gas is sealed up while the hollow part 103 is depressurized. The coefficient of thermal expansion of the back plate glass 104 is lower than that of the front plate glass 102. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a glass panel, and more particularly, to a glass panel including a plate glass on which a phosphor is formed.
[0002]
[Prior art]
The glass panel is composed of a front glass plate and a rear glass plate that face each other through a hollow portion, and an outer peripheral sealing portion that hermetically seals the hollow portion at the periphery of the front glass plate and the rear glass plate, and is used for a plasma display panel (PDP) and the like. Have been.
[0003]
In the glass panel used in this PDP, an electrode film and a dielectric film are formed on a surface facing the hollow portion of the front glass plate and the back glass plate, and a partition wall (rib) film and a phosphor film are formed on the facing surface of the rear glass plate. It is formed. Specifically, a phosphor film is formed on the surface of the rib and faces the electrode film of the front glass.
[0004]
The glass panel arbitrarily displays an image by utilizing light emission of a phosphor irradiated with ultraviolet light generated by ionization of a rare gas in the hollow portion (for example, see Non-Patent Document 1).
[0005]
Each film formed on the front glass plate and the rear glass plate of such a glass panel is formed through printing of raw materials by screen printing, drying of the printed raw materials, and baking of the dried raw materials (for example, Non-Patent Document 2) In general, when a plurality of films are stacked, it is necessary to lower the sintering temperature as a film is stacked later. Therefore, as the number of stacked films increases, the film is formed first. Since it is necessary to raise the firing temperature of the film, the maximum firing temperature of the film of the rear glass sheet is higher than the maximum firing temperature of the film of the front glass sheet.
[0006]
In the glass panel, when an image is displayed, the driving circuit (drive) disposed on the outer surface of the rear plate glass generates heat and the phosphor also generates heat. Therefore, the temperature of the rear plate glass is higher than the temperature of the front plate glass.
[0007]
[Non-patent document 1]
“Matsushita Electric Industrial PDP Reliable Site”, [online], Matsushita Electric Industrial Co., Ltd., [Searched on December 6, 2002], Internet <http://www.panasonic.co.jp/pdp/plasma/index .html>
[Non-patent document 2]
“Thick film process of PPD”, [online], Noritake Company Limited, [searched on December 6, 2002], Internet <http://www.noritake.co.jp/denshi/japanese/fpd/pdp_process01 .htm>
[0008]
[Problems to be solved by the invention]
However, in the conventional glass panel, since the glass sheets having the same composition are used as the front glass sheet and the rear glass sheet, there is no difference in the thermal expansion coefficient between the front glass sheet and the rear glass sheet.
[0009]
At this time, since the maximum firing temperature of the film of the rear glass sheet is higher than the maximum firing temperature of the film of the front glass sheet, a difference occurs in the amount of heat shrinkage when cooled after firing. The relative position between the display electrode and the phosphor of the back plate glass is displaced, and the image cannot be displayed clearly.
[0010]
Also, during image display, the temperature of the rear glass is higher than the temperature of the front glass, so the thermal expansion of the rear glass is larger than the thermal expansion of the front glass, and as a result, the front glass is viewed from the display surface. There is a problem in that the image is curved so as to be concave, and an image cannot be clearly displayed, and particularly, almost no image can be displayed in a perspective direction.
[0011]
Therefore, an object of the present invention is to provide a glass panel that can clearly display an image.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the glass panel according to claim 1, wherein the rear glass sheet is disposed at a predetermined distance from the front glass sheet so as to form a hollow portion between the front glass sheet and the front glass sheet. A glass panel comprising: an outer peripheral sealing portion that hermetically seals the hollow portion at a peripheral portion of the front glass plate and the rear glass plate; and a luminous body applied to a surface of the rear glass plate that faces the hollow portion. The coefficient of thermal expansion of the rear glass sheet is smaller than the coefficient of thermal expansion of the front glass sheet.
[0013]
According to the glass panel of the present invention, since the coefficient of thermal expansion of the rear glass sheet is smaller than the coefficient of thermal expansion of the front glass sheet, there is no difference in the amount of thermal contraction when each film is cooled. In addition to preventing the relative position from being shifted, the amount of thermal expansion of the back glass is almost the same as the amount of thermal expansion of the front glass when displaying images, thereby preventing the front glass from bending as viewed from the display surface. Therefore, images can be clearly displayed.
[0014]
The glass panel according to claim 2 is the glass panel according to claim 1, wherein the outer peripheral sealing portion is made of a low-melting-point material, and is selected from the front glass plate, the back-plate glass, and the low-melting-point material. The absolute value of the difference between the coefficients of thermal expansion is not more than 20 × 10 ⁻⁷ / K.
[0015]
According to the glass panel of the second aspect, the outer peripheral sealing portion is made of a low melting point material, and the absolute value of the difference in thermal expansion coefficient between two selected from the front glass sheet, the rear glass sheet, and the low melting point material is 20. Since it is as small as × 10 ^-7 / K, the front plate glass and the low melting point material are separated from the front plate glass and the low melting point material, and the front plate glass and the low melting point material are separated from the rear plate glass and the low melting point material due to the difference in thermal expansion amount. Separation of the sheet glass and the low melting point material can be prevented.
[0016]
The glass panel according to claim 3 is the glass panel according to claim 2, wherein the coefficient of thermal expansion of the rear glass sheet is α ₁ (10 ⁻⁷ / K), and the coefficient of thermal expansion of the front glass sheet is α ₂ (10 ^−7). / K) and the coefficient of thermal expansion of the low-melting-point material is α _f (10 ⁻⁷ / K), and the relational expression α ₂ −20 ≦ α _f ≦ α ₁ +20 is satisfied.
[0017]
According to the glass panel of the third aspect, the thermal expansion coefficient of the rear glass sheet, the thermal expansion coefficient of the front glass sheet, and the thermal expansion coefficient of the low melting point material satisfy the above relational expression. Peeling of the plate glass and the low melting point material and peeling of the back plate glass and the low melting point material can be reliably prevented.
[0018]
The glass panel according to claim 4 is the glass panel according to any one of claims 1 to 3, wherein the front glass plate is directed from the hollow portion to the outside when the illuminant does not generate heat. Is characterized by having a convex shape.
[0019]
According to the glass panel of the fourth aspect, the front glass has a convex shape in the direction from the hollow portion to the outside when the luminous body is not generating heat. The amount of expansion and the amount of thermal expansion of the rear glass plate can be made almost the same, and when displaying images, the front glass plate can be reliably prevented from bending when viewed from the display surface, so that images can be displayed more clearly. it can.
[0020]
The glass panel according to claim 5, wherein in the glass panel according to any one of claims 1 to 3, when the luminous body generates heat, the thermal expansion amount of the front glass plate and the thermal expansion amount of the rear glass plate are different. It is characterized by being substantially the same.
[0021]
According to the glass panel of the fifth aspect, when the luminous body generates heat, the thermal expansion of the front glass and the thermal expansion of the rear glass are substantially the same. It is possible to more reliably prevent the front glass from being curved as viewed from the display surface by setting the thermal expansion of the front glass almost the same as that of the front glass, so that an image can be displayed more clearly.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a glass panel according to a first embodiment of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 is a diagram showing a schematic configuration of a PDP made of a glass panel according to the first embodiment, in which (a) is a perspective view and (b) is a partial cross-sectional view.
[0024]
In FIG. 1, a PDP 100 includes a glass panel 101 according to the first embodiment. The glass panel 101 is disposed at a distance of, for example, 0.1 mm from the front glass 102 so as to form a hollow portion 103 between the front glass 102 having a thickness of, for example, 2.8 mm and the front glass 102. And a rear glass plate 104 having a thickness of, for example, 2.8 mm. The front glass plate 102 and the rear glass plate 104 have a low-melting-point glass paste at the outer peripheral edge thereof in order to seal a rare gas while reducing the pressure in the hollow portion 103. Is sealed by a sealing portion 105 (outer peripheral sealing portion) made of. In addition, the coefficient of thermal expansion of the back glass 104 in the glass panel 101 is smaller than the coefficient of thermal expansion of the front glass 102.
[0025]
On the inner surface of the front glass plate 102, a display electrode 106 composed of a transparent electrode 106a and a metal electrode 106b is pattern-formed, and a dielectric glass layer 107 is laminated so as to cover the display electrode 106. Is laminated with a dielectric protection layer 108 made of magnesium oxide (MgO).
[0026]
Further, on the inner surface of the back plate glass 104, address electrodes 109 for controlling light emission of phosphors 113 to 115 described later are patterned at a predetermined pitch, and a dielectric glass layer 110 is laminated so as to cover the address electrodes 109. A plurality of glass ribs 112 defining a plurality of channel-shaped discharge spaces 111 are pattern-formed on the dielectric glass layer 110 by a sandblast method or a blade molding method, and the surface of the rib 112 in each discharge space 111 is formed. Is coated with a red (R) phosphor 113, a green (G) phosphor 114, and a blue (B) phosphor 115 sequentially in order to perform color display.
[0027]
The rib 112 has a height of, for example, 0.1 mm, and keeps a distance between the front glass plate 102 and the rear glass plate 104 at about 0.1 mm. The discharge space 111 is filled with a rare gas. As the rare gas, for example, a mixed gas system having a composition of neon (Ne) and xenon (Xe) is used, the sealing pressure thereof is set in a range of about 40 to 70 kPa, and the degree of vacuum of the discharge space 111 is, for example, It is about 1.33 Pa (10 ^-2 Torr).
[0028]
Then, the phosphors 113 to 115 are excited and emit light by ultraviolet rays having a short wavelength generated by the discharge to the discharge space 111.
[0029]
Hereinafter, a method of manufacturing the PDP 100 of FIG. 1 will be described.
[0030]
FIG. 2 is a flowchart illustrating a manufacturing process of the PDP 100 of FIG.
[0031]
In FIG. 2, first, a through hole (not shown) is formed in the rear glass plate 104 (step S201), and an address electrode 109, a dielectric glass layer 110, a rib 111, and phosphors 113 to 115 are formed on the inner surface of the rear glass plate 104. Are sequentially formed, while the display electrode 106, the dielectric glass layer 107, and the dielectric protective layer 108 are sequentially formed on the inner surface of the front glass plate 102 (step S202).
[0032]
Then, a low-melting glass paste is applied as a sealing material for sealing the front glass plate 102 to the peripheral portion of the PDP 100 where the rear glass plate 104 and the front glass plate 102 overlap, and calcined at about 350 ° C. Is removed (step S203).
[0033]
Next, the front glass plate 102 is arranged on the inner surface side of the rear glass plate 104 so that the display electrode 106 and the address electrode 109 are orthogonal to each other (step S204), and the calcined low melting point glass paste is fired at about 450 ° C. Is formed to seal the front glass plate 102 and the rear glass plate 104 (step S205). At this time, since the phosphors 113 to 115 are deteriorated by water vapor generated by heating at the time of sealing, when sealing the front glass plate 102 and the rear glass plate 104, dry air is introduced into the hollow portion 103 through the exhaust hole. I do.
[0034]
Next, the glass panel 101 is heated to about 350 ° C., and the dry air in the hollow portion 103 is exhausted through an exhaust hole. Then, a rare gas is supplied until the inside of the glass panel 101 reaches a predetermined degree of vacuum, for example, 1.33 Pa. Introduced (step S206), the exhaust hole is sealed (step S207), and the process ends.
[0035]
Next, the formation of various films in step S202 in the process of FIG. 2 will be described.
[0036]
FIG. 3 is a process diagram illustrating a process of forming various films laminated on the inner surface of the front glass plate 102 in FIG. 1. FIG. 4 is a process diagram of various films laminated on the inner surface of the rear glass plate 104 in FIG. It is a process drawing explaining a formation process.
[0037]
In FIG. 3, first, an electrode film is printed on the inner surface of the front glass plate 102 at a predetermined pitch by screen printing, and the printed electrode film is dried and fired for a predetermined time to form the display electrode 106 (FIG. a)).
[0038]
Thereafter, a dielectric film made of glass is applied to the entire surface on the inner surface of the front glass plate 102 so as to cover the display electrode 106, and the applied dielectric film is dried and fired for a predetermined time to form the dielectric glass layer 107. Then, a dielectric protection layer 108 is laminated on the formed dielectric glass layer 107 (FIG. 3C).
[0039]
In the step of FIG. 3, the above-described applied films are fired at a temperature of about 550 ° C. to 450 ° C. When firing a film to be formed later, the already formed film is not melted again. The sintering temperature decreases as the film is formed later.
[0040]
In FIG. 4, first, an electrode film is printed at a predetermined pitch on the inner surface of the back plate glass 104 by screen printing, and the printed electrode film is dried and fired for a predetermined time to form an address electrode 109 (FIG. 4 (a)).
[0041]
After that, a dielectric film made of glass is applied to the entire surface of the inner surface of the rear glass plate 104 so as to cover the address electrode 109, and the applied dielectric film is dried and fired for a predetermined time to form the dielectric glass layer 110. A glass paste is formed over the entire surface of the formed dielectric glass layer 110 (FIG. 4B), and a plurality of the applied glass pastes are equally spaced by a masking method or a blade molding method. Is formed in a partition shape so as to define the channel-shaped discharge space 111. Thereafter, the ribs 112 are formed through drying and firing of the glass paste formed into a partition shape for a predetermined time (FIG. 4C).
[0042]
Then, the phosphor paste corresponding to each of the phosphors 113 to 115 is screen-printed on the surface of the rib 112, and after drying for a predetermined time, the resin components and the like are removed by baking at about 500 ° C. Steps 113 to 115 are formed (FIG. 4D).
[0043]
In the step of FIG. 4, the applied various films are fired at a temperature of about 600 ° C. to 500 ° C. As in the step of FIG.
[0044]
Therefore, the maximum baking temperature of the film formed on the inner surface of the rear glass plate 104 is higher than the maximum baking temperature of the film formed on the inner surface of the front glass plate 102. Since the coefficient of thermal expansion of the back glass 104 is smaller than the coefficient of thermal expansion of the front glass 102, the amount of thermal expansion of the film of the front glass 102 and the amount of thermal expansion of the film of the back glass 104 are substantially the same.
[0045]
According to the glass panel according to the first embodiment, since the coefficient of thermal expansion of the rear glass sheet 104 is smaller than the coefficient of thermal expansion of the front glass sheet 102, there is no difference in the amount of thermal contraction when each film is cooled. It is possible to prevent the relative position between the electrode 106 and the phosphors 113 to 115 from being shifted, and to make the amount of thermal expansion of the back glass 104 substantially equal to the amount of thermal expansion of the front glass 102 when displaying an image. The plate glass 102 can be prevented from being curved when viewed from the display surface, so that a clear image can be displayed.
[0046]
In the glass panel 101, the absolute value of the difference in the coefficient of thermal expansion between two selected from the front glass plate 102, the rear glass plate 104, and the sealing portion 105 is preferably 20 × 10 ⁻⁷ / K or less. In particular, the coefficient of thermal expansion of the back glass 104 is α ₁ (10 ⁻⁷ / K), the coefficient of thermal expansion of the front glass 102 is α ₂ (10 ⁻⁷ / K), and the coefficient of thermal expansion of the sealing portion 105 is α. _{When f} (10 ⁻⁷ / K), it is preferable to satisfy the relational expression α ₂ −20 ≦ α _f ≦ α ₁ +20. Thereby, the front plate glass 102 and the sealing portion 105 are separated from each other, and the front plate glass 102 and the sealing portion 105 are separated from each other due to the difference in the amount of thermal expansion between the rear plate glass 104 and the sealing portion 105. Peeling of the sealing portion 104 and the sealing portion 105 can be reliably prevented.
[0047]
The thermal expansion coefficients of the front glass plate 102, the rear glass plate 104, and the sealing portion 105 may be adjusted by a known method such as adjusting the amount of an alkaline earth metal added to the glass composition.
[0048]
Next, a glass panel according to a second embodiment of the present invention will be described with reference to the drawings.
[0049]
The configuration of the glass panel according to the second embodiment is the same as that of the glass panel according to the first embodiment except for the front glass 501 and the rear glass 502, which will be described later. Therefore, only different parts will be described.
[0050]
5A and 5B are diagrams showing a schematic configuration of a PDP made of a glass panel according to the second embodiment, wherein FIG. 5A is a partial cross-sectional view, and FIG. 5B is a cross-sectional view.
[0051]
In FIG. 5, a PDP 500 includes a glass panel 501 according to the second embodiment. In the glass panel 501, the front plate glass 502 has a convex shape in the direction from the hollow portion 103 to the outside when the phosphors 113 to 115 are not generating heat (FIG. 5B). When such a convex shape is used to generate the glass sheet used for the front glass sheet 502 by the float method, the hot water temperature of the float bath to which the float surface of the glass sheet is exposed and the atmosphere temperature in the furnace to which the top surface of the glass sheet is exposed Is formed by a method of adjusting.
[0052]
The phosphors 113 to 115 generate heat when emitting light. In the glass panel 501, the phosphors 113 to 115 are applied to the surface of the rib 112 formed on the inner surface of the back plate glass 503 as described above. Since the rib 112 is in contact with the front glass plate 502 only at its tip, heat generated by light emission is easily transferred to the rear glass plate 503 naturally. Further, a drive (not shown) is provided on the outer surface of the rear glass plate 503, and the heat of the drive is easily transferred to the rear glass plate 503. Therefore, when the phosphors 113 to 115 emit light, the temperature rise ΔT ₁ (K) of the rear glass 503 is larger than the temperature rise ΔT ₂ (K) of the front glass 502.
[0053]
Accordingly, the amount of thermal expansion of the back glass 503 is increased. At this time, since the front glass 502 and the back glass 503 are restrained from moving with each other by the sealing portion 105 at the peripheral edge, the front glass 502 is placed on the display surface. Bending force is applied to the front glass plate 502. However, since the front glass plate 502 has a convex shape in the direction from the hollow portion 103 to the outside, the front glass plate 502 has a substantially planar shape due to the load of the bending force.
[0054]
The method of manufacturing PDP 500 is the same as the method of manufacturing PDP 100 described above, and a description thereof will not be repeated.
[0055]
According to the glass panel of the second embodiment, the front glass 502 has a convex shape with respect to the direction from the hollow portion 103 to the outside, so that the temperature rise ΔT ₁ (K) of the rear glass 503 and the front glass 502 Even when a bending force caused by a difference from the temperature rise ΔT ₂ (K) is applied to the front glass plate 502, the front glass plate 502 assumes a substantially planar shape, and when an image is displayed, the front glass plate 502 is curved as viewed from the display surface. Can be reliably prevented, and the image can be clearly displayed.
[0056]
In the above-described glass panel 501, the front glass plate 502 does not exhibit a convex shape in the direction from the hollow portion 103 to the outside, and instead has a coefficient of thermal expansion of the rear glass plate 503 of α ₃ (10 ⁻⁷ / K), When the coefficient of thermal expansion of the front glass plate 502 is α ₄ (10 ⁻⁷ / K), α ₃ and α ₄ may be set to satisfy α ₃ × ΔT ₁ = α ₄ × ΔT _2. preferable. Accordingly, when the phosphors 113 to 115 generate heat, the thermal expansion of the front glass 502 and the thermal expansion of the rear glass 503 are substantially the same. Therefore, when displaying an image, the thermal expansion of the rear glass 503 is reduced. The front glass plate 502 can be reliably prevented from being curved when viewed from the display surface, with substantially the same thermal expansion amount as that of the display plate 502, so that an image can be displayed more clearly.
[0057]
The configurations according to the first and second embodiments of the present invention described above can be applied not only to the plasma display panel, but also to all display panels including a luminous body that generates heat.
[0058]
In the above-described glass panels 101 and 501, the sealing between the front glass plate 102 or 502 and the rear glass plate 104 or 503 is performed by firing a low-melting glass paste. It may be performed by inflow.
[0059]
As the composition of each of the front glass plate 102 or 502 and the rear glass plate 104 or 503, soda silicate glass, soda lime glass, borosilicate glass, aluminosilicate glass, various crystallized glasses, and the like can be used. In order to obtain heat resistance having a coefficient of thermal expansion substantially equal to that of glass and a strain point higher than that, SiO ₂ : 56 to 68%, Al ₂ O ₃ : 0.2 to 5% , ZrO ₂ : 0 to 6.4%, Li ₂ O: 0 to 0.5%, Na ₂ O: 0.2 to 8%, K ₂ O: 2.5 to 14%, MgO: 1 to 7% , CaO: 2 to 12%, SrO: 0 to 12%, BaO: 0 to 13%, ZnO: 0 to 2%, SO ₃ + Sb ₂ O ₃ : 0 to 1%, TiO ₂ : 0 to 3% _{, Na 2 O + K 2 O} : 7~17%, MgO + CaO: 7~15%, SrO BaO: 4~18%, MgO + CaO + SrO + BaO: a 15 to 27%, preferably the total of SiO _2, Al ₂ O ₃ and ZrO ₂ is 58 wt% or more, the back plate glass 104, 50 to 350 ° C. Preferably has an average coefficient of thermal expansion of 75 to 100 × 10 ⁻⁷ / K and a strain point of 530 ° C. or higher.
[0060]
【The invention's effect】
As described in detail above, according to the glass panel of claim 1, since the coefficient of thermal expansion of the rear glass sheet is smaller than the coefficient of thermal expansion of the front glass sheet, there is no difference in the amount of thermal contraction when cooling each film. It is possible to prevent the relative position between the display electrode and the phosphor from being displaced, and at the time of displaying an image, the amount of thermal expansion of the back glass is almost the same as the amount of thermal expansion of the front glass so that the front glass is moved from the display surface. It can be prevented from being curved when viewed, so that the image can be displayed clearly.
[0061]
According to the glass panel of the second aspect, the outer peripheral sealing portion is made of a low melting point material, and the absolute value of the difference in thermal expansion coefficient between two selected from the front glass sheet, the rear glass sheet, and the low melting point material is 20. Since it is as small as × 10 ⁻⁷ / K or less, the front plate glass and the low melting point material are separated from the front plate glass and the low melting point material, and the front plate glass and the low melting point material are separated due to the difference in the thermal expansion amount between the rear plate glass and the low melting point material. Separation of the back plate glass and the low melting point material can be prevented.
[0062]
According to the glass panel of the third aspect, the thermal expansion coefficient of the rear glass sheet, the thermal expansion coefficient of the front glass sheet, and the thermal expansion coefficient of the low melting point material satisfy the above relational expression. Peeling of the plate glass and the low melting point material and peeling of the back plate glass and the low melting point material can be reliably prevented.
[0063]
According to the glass panel of the fourth aspect, the front glass has a convex shape in the direction from the hollow portion to the outside when the luminous body is not generating heat. The amount of expansion and the amount of thermal expansion of the rear glass plate can be made almost the same, and when displaying images, the front glass plate can be reliably prevented from bending when viewed from the display surface, so that images can be displayed more clearly. it can.
[0064]
According to the glass panel of the fifth aspect, when the luminous body generates heat, the thermal expansion of the front glass and the thermal expansion of the rear glass are substantially the same. It is possible to more reliably prevent the front glass from being curved as viewed from the display surface by setting the thermal expansion of the front glass almost the same as that of the front glass, so that an image can be displayed more clearly.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams showing a schematic configuration of a PDP made of a glass panel according to a first embodiment of the present invention, wherein FIG. 1A is a perspective view and FIG. 1B is a partial sectional view.
FIG. 2 is a flowchart illustrating a manufacturing process of the PDP 100 of FIG.
FIG. 3 is a process diagram illustrating a process of forming various films laminated on the inner surface of the front glass plate 102 in FIG.
FIG. 4 is a process chart for explaining a process of forming various films laminated on the inner surface of the back plate glass 104 in FIG.
5A and 5B are diagrams showing a schematic configuration of a PDP made of a glass panel according to a second embodiment of the present invention, wherein FIG. 5A is a partial cross-sectional view, and FIG. 5B is a cross-sectional view.
[Explanation of symbols]
100,500 PDP
101,501 Glass panel 102,502 Front plate glass 103 Hollow portion 104,503 Back plate glass 105 Sealing portion 112 Rib 113,114,115 Phosphor

Claims (5)

A front glass sheet, a rear glass sheet disposed at a predetermined distance from the front glass sheet so as to form a hollow section between the front glass sheet, and the hollow section at a peripheral edge of the front glass sheet and the rear glass sheet. In a glass panel comprising an outer peripheral sealing portion that hermetically seals, and a luminous body applied to a surface of the back plate glass facing the hollow portion,
A glass panel, wherein a coefficient of thermal expansion of the rear glass sheet is smaller than a coefficient of thermal expansion of the front glass sheet. The outer peripheral sealing portion is made of a low melting point material, and an absolute value of a difference between thermal expansion coefficients of two selected from the front glass sheet, the back glass sheet, and the low melting point material is 20 × 10 ⁻⁷ / K or less. The glass panel according to claim 1, wherein The coefficient of thermal expansion of the rear glass sheet is α ₁ (10 ⁻⁷ / K), the coefficient of thermal expansion of the front glass sheet is α ₂ (10 ⁻⁷ / K), and the coefficient of thermal expansion of the low melting point material is α _f (10 ⁻⁷ / K), the following relational expression α ₂ −20 ≦ α _f ≦ α ₁ +20
3. The glass panel according to claim 2, wherein: 4. The glass panel according to claim 1, wherein the front plate glass has a convex shape in a direction from the hollow portion to the outside when the luminous body does not generate heat. 5. The glass panel according to any one of claims 1 to 3, wherein, when the luminous body generates heat, the amount of thermal expansion of the front glass plate and the amount of thermal expansion of the back glass plate are substantially the same.

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