Glass panel unit
A glass panel unit includes a first pane of glass, and a second pane of glass facing the first pane of glass with both of them spaced a predetermined interval apart. It is provided with a sealant between the panes of glass, joined to them in an airtight manner, and an interior space sealed with them and the sealant. It is provided with a first spacer in the interior space so as to be in contact with the panes of glass, and a second spacer disposed in the interior space so as to be in contact with only one of the panes of glass and out of contact with another thereof.
1. A glass panel unit, comprising:
a first pane of glass;
a second pane of glass that faces the first pane of glass with the first pane of glass and the second pane of glass spaced a predetermined interval apart;
a sealant that is disposed between the first pane of glass and the second pane of glass and joined to the first pane of glass and the second pane of glass in an airtight manner;
an interior space that is sealed with the first pane of glass, the second pane of glass and the sealant;
a plurality of first spacers that are disposed in the interior space, the plurality of first spacers being in contact with the first pane of glass and the second pane of glass; and
a plurality of second spacers that is disposed in the interior space, the plurality of second spacers being in contact with only the second pane of glass, out of contact with the first pane of glass,
the plurality of second spacers being configured to be out of contact with the first pane of glass when the first pane of glass and the second pane of glass receive no force other than atmospheric pressure and to be in contact with the first pane of glass when the first pane of glass is bent, and
one or more of the plurality of second spacers being arranged between two of the plurality of first spacers, respectively.
2. The glass panel unit of claim 1 , wherein each of the plurality of second spacers is 100 μm or less in maximum length in a direction perpendicular to a pane surface of the glass panel unit.
3. The glass panel unit of claim 1 , wherein each of the plurality of second spacers is composed of an elastic member.
4. The glass panel unit of claim 1 , wherein each of the plurality of second spacers is made from transparent material.
5. The glass panel unit of claim 1 ,
wherein as viewed along a direction perpendicular to a pane surface of the glass panel unit,
a ratio of a total area of the plurality of first spacers to an area of the pane surface is greater than or equal to 0.05% and less than or equal to 0.2%, and
a ratio of a total area of the plurality of second spacers to an area of the pane surface is greater than or equal to 0.05% and less than or equal to 0.2%.
6. The glass panel unit of claim 5 , wherein
the ratio of the total area of the plurality of first spacers to the area of the pane surface is greater than or equal to 0.05% and less than or equal to 0.1%, and
the ratio of the total area of the plurality of second spacers to the area of the pane surface is greater than or equal to 0.15%.
7. The glass panel unit of claim 1 , wherein the plurality of second spacers are arranged irregularly.
8. The glass panel unit of claim 1 , wherein the plurality of first spacers are arranged irregularly.
9. The glass panel unit of claim 1 , wherein a low-emissivity film is formed on the first pane of glass.
10. The glass panel unit of claim 1 , further comprising:
a third pane of glass facing the second pane of glass;
a second sealant that is disposed between the second pane of glass and the third pane of glass and joined to the second pane of glass and the third pane of glass in an airtight manner; and
a second interior space that is sealed with the second pane of glass, the third pane of glass and the second sealant and filled with dry gas.
11. A windowpane, comprising:
a glass panel unit of claim 1 , and
a window frame that a periphery of the glass panel unit is fit in.
12. The glass panel unit of claim 1 , further comprising:
a third pane of glass facing the first pane of glass;
a second sealant that is disposed between the first pane of glass and the third pane of glass and joined to the first pane of glass and the third pane of glass in an airtight manner; and
a second interior space that is sealed with the first pane of glass, the third pane of glass and the second sealant and filled with dry gas.