Rearview mirror for motor vehicles

• US 7,156,533 B2
• Filed: 01/31/2006
• Issued: 01/02/2007
• Est. Priority Date: 02/02/2005
• Status: Active Grant

• Current Assignee: Flabeg Automotive Germany GmbH (FLABEG Automotive Glass Group GmbH)
• Original Assignee: Flabeg GmbH & Co. KG
• Inventors: Hoeing, Thomas
• Primary Examiner(s): Shafer; Ricky D.
• Application Number:
  US11/343,334
• Publication Number:
  US 20060181760A1
• Time in Patent Office: 336 Days
• Field of Search: 359/883, 359/884, 359/603, 359/507, 359/267, 359/584, 359/585, 359/589
• US Class Current: 359/883
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/3636 one layer at least containing silicon, hydrogenated silicon or a silicide
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/3663 specially adapted for use as mirrors
• CPC Class Codes: C03C 2217/71 Photocatalytic coatings
• CPC Class Codes: C03C 2217/75 Hydrophilic and oleophilic coatings
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate
• CPC Class Codes: G02B 5/0816 Multilayer mirrors, i.e. having two or more reflecting layers G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/085 at least one of the reflecting layers comprising metal

Abstract

A rearview mirror for motor vehicles having a layer substrate and a coating applied onto the back thereof, includes a reflective mirror coating and an intermediate layer, which may be made of a semiconductor material, arranged between the reflective mirror coating and the layer substrate. The value of the coloring parameter C=√{square root over (a₀²+b₀²)} is greater than 5 and the color change ΔE resulting from a tilting of the rearview mirror by 45° from the perpendicular viewing angle as a function of the magnitude of the color value a₀ according to CIE is not greater than
ΔE≦½·(|a₀|−8) wherein a₀≦−20,
ΔE≦6 wherein −20≦a₀≦0, and
ΔE≦½·(a₀+12), especially ≦½·(a₀−3), preferably ≦⅓·(a₀−3), advantageously ≦⅙·(a₀−3), wherein a₀≦0.
The intermediate layer may be made of semiconductor material.

Claims

1. A rearview mirror for motor vehicles moveable between a perpendicular viewing angle to a tilted position 45°

from the perpendicular viewing angle, comprising;

a layer substrate; and

a coating applied to the layer substrate, the coating including a reflective mirror coating and an intermediate layer disposed between the reflective mirror coating and the layer substrate, wherein a magnitude of a parameter for coloring C=√

{square root over (a₀²+b₀²)} is greater than 5 wherein a₀ represents a first color coordinate value and b₀ represents a second color coordinate value at a perpendicular light incidence according to CIE and a color change Δ

E resulting from a tilting of the rearview mirror to the tilted position as a function of a magnitude of the first color coordinate value a₀ is given by;

Δ

E≦

½

·

(|a₀|−

8) when a₀≦

−

20;

Δ

E≦

6 when −

20≦

a₀≦

0;

or

Δ

E≦

½

·

(a₀+12), when a₀≧

0.

2. The rearview mirror as recited in claim 1, wherein the color change Δ

E is ≦

⅓

·

(a₀−

3) when a₀≧

0.

3. The rearview mirror as recited in claim 2, wherein the color change Δ

E is ≦

⅙

·

(a₀−

3) when a₀≧

0.

4. The rearview mirror as recited in claim 1, wherein the color value a₀>

0 is selected.

5. The rearview mirror as recited in claim 4, wherein the color change Δ

E is not greater than 18.

6. The rearview mirror as recited in claim 1, wherein the intermediate layer includes a semiconductor material.

7. The rearview mirror as recited in claim 6, wherein the semiconductor material includes at least one of silicon and germanium.

8. The rearview mirror as recited in claim 6, wherein the intermediate layer includes the semiconductor material mixed with at least one of nitrogen, hydrogen and oxygen.

9. The rearview mirror as recited in claim 6, wherein the semiconductor material includes an optical layer thickness of between 135 nm up to 240 nm.

10. The rearview mirror as recited in claim 6, wherein the semiconductor material includes an optical layer thickness of between 135 nm up to 240 nm plus an integral multiple of 275 nm.

11. The rearview mirror as recited in claim 6, wherein intermediate layer has a multilayered structure and includes a plurality of semiconductor layers.

12. The rearview mirror as recited in claim 6, wherein the intermediate layer includes a plurality of dielectric layers.

13. The rearview mirror as recited in claim 12, wherein each of the plurality of dielectric layers includes tin oxide (SnO₂).

14. The rearview mirror as recited in claim 12, wherein the entirety of dielectric layers includes an optical layer thickness of less than 240 nm.

15. The rearview mirror as recited in claim 12, wherein the entirety of dielectric layers includes an optical layer thickness of less than 160 nm plus an integral multiple of 275 nm.

16. The rearview mirror as recited in claim 1, wherein the color change Δ

E is not greater than 18.

17. The rearview mirror as recited in claim 1, wherein a ratio of reflection values to a darkness-adapted eye to reflection values to a light-adapted eye light types A and C, respectively, is not more than most 90%.

18. The rearview mirror as recited in claim 1, wherein a reflection factor for light type A is at least 40%.

19. The rearview mirror as recited in claim 18, wherein the reflection factor for light type A is advantageously not more than 70%.

20. The rearview mirror as recited in claim 1, wherein the mirror coating includes at least one of silver, aluminum, chromium, nickel, and titanium.

21. The rearview mirror as recited in claim 1, wherein the mirror coating includes an alloy including at least one of silver, aluminum, chromium, nickel, and titanium.

22. The rearview mirror as recited in claim 1, wherein the intermediate layer is applied to the layer substrate using cathodic sputtering.

23. The rearview mirror as recited in claim 1, wherein the layer substrate includes a soda-silicate glass.

24. The rearview mirror as recited in claim 1, wherein the intermediate layer is amorphous.

25. The rearview mirror as recited in claim 1, wherein the intermediate layer has a mean layer thickness of 3 nm to 200 nm.

26. The rearview mirror as recited in claim 25, wherein the mean layer thickness is 40 nm to 80 nm.

27. The rearview mirror as recited in claim 1, wherein a degree of transmission of the rearview mirror is not more than 10%.

28. The rearview mirror as recited in claim 27, wherein the degree of transmission is not more than 2%.