Vehicle window plate
A vehicle window plate has a maximum value of a variation of a curvature in a vertical direction being ±7.6E-6 mm −2 or less at least within a HUD display area. The curvature preferably increases monotonically from a lower side to an upper side at least within the HUD display area.
1. A vehicle window plate, wherein:
a maximum value of a variation of a curvature in a vertical direction is ±7.6E-6 mm −2 or less at least within a HUD display area of the vehicle window plate; and
a position most distant from a chord connecting an upper side and a lower side serving as a reference is located more closely to the upper side than a center position in the vertical direction.
2. The vehicle window plate according to claim 1 , wherein:
the curvature increases monotonically from the lower side to the upper side at least within the HUD display area.
3. The vehicle window plate according to claim 1 , wherein:
an average value of the variation of the curvature in the vertical direction is ±1.2E-6 mm −2 or less at least within the HUD display area.
4. The vehicle window plate according to claim 1 , wherein:
the variation of the curvature is constant at least within the HUD display area.
5. The vehicle window plate according to claim 1 , wherein:
a difference in curvatures between a left end portion and a right end portion is 0.00040 mm −1 or less at least within the HUD display area.
6. The vehicle window plate according to claim 1 , wherein:
a maximum value of the curvature is 0.001 mm −1 or less at least within the HUD display area.
7. The vehicle window plate according to claim 1 , wherein:
the HUD display area is 10 cm 2 or more.
8. The vehicle window plate according to claim 1 , wherein:
the vehicle window plate is a glass plate;
the glass plate has an area where a plane stress is formed at an outer peripheral edge and inside the outer peripheral edge; and
the HUD display area dose not overlap with the area where the plane stress is formed.
9. The vehicle window plate according to claim 2 , wherein:
an average value of the variation of the curvature in the vertical direction is ±1.2E-6 mm −2 or less at least within the HUD display area.
10. The vehicle window plate according to claim 2 , wherein:
a difference in curvatures between a left end portion and a right end portion is 0.00040 mm −1 or less at least within the HUD display area.
11. The vehicle window plate according to claim 2 , wherein:
a maximum value of the curvature is 0.001 mm −1 or less at least within the HUD display area.
12. The vehicle window plate according to claim 2 , wherein:
the HUD display area is 10 cm 2 or more.
13. The vehicle window plate according to claim 2 , wherein:
the vehicle window plate is a glass plate;
the glass plate has an area where a plane stress is formed at an outer peripheral edge and inside the outer peripheral edge; and
the HUD display area dose not overlap with the area where the plane stress is formed.
14. The vehicle window plate according to claim 3 , wherein:
a difference in curvatures between a left end portion and a right end portion is 0.00040 min −1 or less at least within the HUD display area.
15. The vehicle window plate according to claim 3 , wherein:
a maximum value of the curvature is 0.001 mm −1 or less at least within the HUD display area.
16. The vehicle window plate according to claim 3 , wherein:
the HUD display area is 10 cm 2 or more.
17. The vehicle window plate according to claim 3 , wherein:
the vehicle window plate is a glass plate;
the glass plate has an area where a plane stress is formed at an outer peripheral edge and inside the outer peripheral edge; and
the HUD display area dose not overlap with the area where the plane stress is formed.
18. The vehicle window plate according to claim 4 , wherein:
a difference in curvatures between a left end portion and a right end portion is 0.00040 mm −1 or less at least within the HUD display area.
19. The vehicle window plate according to claim 4 , wherein:
a maximum value of the curvature is 0.001 mm −1 or less at least within the HUD display area.
20. The vehicle window plate according to claim 4 , wherein:
the HUD display area is 10 cm 2 or more.