Laminated glass

1. A laminated glass comprising:

a first glass plate to be arranged on an inner side of a vehicle;

a second glass plate to be arranged on an outer side of the vehicle;

an interlayer located between the first glass plate and the second glass plate and bonded to the first glass plate and the second glass plate; and

a display area configured to be used for a head up display,

wherein the display area includes a region having a wedge shape in a cross section, a thickness at an upper end of the region in a vertical direction being greater than a thickness at a lower end of the region, when the laminated glass is installed on the vehicle,

wherein a difference in thickness, Δt [mm], between a thickness of the laminated glass at a thickest portion in the display area and a thickness of the laminated glass at a thinnest portion in the display area, and a difference in visible light transmittance, ΔTv [%], between a visible light transmittance of the laminated glass at the thickest portion in the display area and a visible light transmittance of the laminated glass at the thinnest portion in the display area, satisfy a relation of ΔTv≥2.2 Δt, and

wherein a member with a lowest visible light transmittance per unit thickness from among the first glass plate, the second glass plate and the interlayer has a wedge shape in a cross section.

2. The laminated glass according to claim 1 ,

wherein the difference in thickness, Δt [mm], and the difference in visible light transmittance, ΔTv [%], satisfy a relation of ΔTv≥2.4 Δt.

3. The laminated glass according to claim 2 ,

wherein the difference in thickness, Δt [mm], and the difference in visible light transmittance, ΔTv [%], satisfy a relation of ΔTv≥2.6 Δt.

4. The laminated glass according to claim 1 ,

wherein either or both of the first glass plate and the second glass plate has a wedge shape in a cross section.

5. The laminated glass according to claim 1 ,

wherein the interlayer has a wedge shape in a cross section, and

wherein a thickness of the interlayer at a thinnest portion in the display area is 0.65 mm or more.

6. The laminated glass according to claim 1 ,

wherein the interlayer includes a polyvinyl butyral resin, and the first glass plate and the second glass plate are formed of a green glass.

7. The laminated glass according to claim 1 ,

wherein an average value of a wedge angle in the region having a wedge shape in a cross section is 1.5 mrad or less.

8. The laminated glass according to claim 1 ,

wherein an average value of a wedge angle in the region having a wedge shape in a cross section is 0.4 mrad or less.

9. The laminated glass according to claim 1 ,

wherein a radius of curvature of the laminated glass in the vertical direction is 6000 mm or more.

10. A laminated glass comprising:

a first glass plate to be arranged on an inner side of a vehicle;

a second glass plate to be arranged on an outer side of the vehicle;

an interlayer located between the first glass plate and the second glass plate and bonded to the first glass plate and the second glass plate; and

a display area configured to be used for a head up display,

wherein the display area includes a region having a wedge shape in a cross section, a thickness at an upper end of the region in a vertical direction being greater than a thickness at a lower end of the region, when the laminated glass is installed on the vehicle,

wherein a difference in thickness, Δt [mm], between a thickness of the laminated glass at a thickest portion in the display area and a thickness of the laminated glass at a thinnest portion in the display area, and a difference in visible light transmittance, ΔTv [%], between a visible light transmittance of the laminated glass at the thickest portion in the display area and a visible light transmittance of the laminated glass at the thinnest portion in the display area, satisfy a relation of ΔTv≥2.2 Δt, and

wherein a wedge angle in an area from an upper end of the display area to an upper end of the laminated glass is less than a wedge angle in the region having a wedge shape in a cross section.

11. The laminated glass according to claim 10 ,

wherein the difference in thickness, Δt [mm], and the difference in visible light transmittance, ΔTv [%], satisfy a relation of ΔTv≥2.4 Δt.

12. The laminated glass according to claim 11 ,

wherein the difference in thickness, Δt [mm], and the difference in visible light transmittance, ΔTv [%], satisfy a relation of ΔTv≥2.6 Δt.

13. The laminated glass according to claim 10 ,

wherein a member with a lowest visible light transmittance per unit thickness from among the first glass plate, the second glass plate and the interlayer has a wedge shape in a cross section.

14. The laminated glass according to claim 13 ,

wherein either or both of the first glass plate and the second glass plate has a wedge shape in a cross section.

15. The laminated glass according to claim 13 ,

wherein a member with a lowest visible light transmittance per unit thickness from among the first glass plate, the second glass plate and the interlayer has a wedge shape in a cross section,

wherein the interlayer has a wedge shape in a cross section, and

wherein a thickness of the interlayer at a thinnest portion in the display area is 0.65 mm or more.

16. The laminated glass according to claim 10 ,

wherein the interlayer includes a polyvinyl butyral resin, and the first glass plate and the second glass plate are formed of a green glass.

17. The laminated glass according to claim 10 ,

wherein an average value of a wedge angle in the region having a wedge shape in a cross section is 1.5 mrad or less.

18. The laminated glass according to claim 10 ,

wherein an average value of a wedge angle in the region having a wedge shape in a cross section is 0.4 mrad or less.

19. The laminated glass according to claim 10 ,

wherein a radius of curvature of the laminated glass in the vertical direction is 6000 mm or more.