Anti-glare rearview mirror assembly and reflectance control method of same

• US 6,974,940 B2
• Filed: 01/23/2003
• Issued: 12/13/2005
• Est. Priority Date: 11/21/2002
• Status: Expired due to Fees

• Current Assignee: Exon Science, Inc.
• Original Assignee: Exon Science, Inc.
• Inventors: Hsiao, Shun-Hsiang, Chen, Kuei-Hung, Su, Wen-Wei
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): MONBLEAU, DAVIENNE N
• Application Number:
  US10/350,246
• Publication Number:
  US 20040099786A1
• Time in Patent Office: 1,055 Days
• Field of Search: 250/201.1, 250204-206, 250/216, 250/578.1, 356/448, 359601-605, 359/265
• US Class Current: 250/204
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: G01J 1/26 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00

Abstract

An anti-glare rearview mirror assembly and a reflectance control method thereof are disclosed. The assembly includes an electrochromic rearview mirrors, two rearward light sensors, and a comparative controller. The sensors receiving a first rearward light from a first specified region and a second rearward light from a second specified region at the same time point, respectively, wherein the first and second specified regions partially overlap with each other. The intensities of the first and second rearview mirror light are compared to obtain a light difference. The reflectance of the anti-glare rearview mirror is adjusted according to the light difference.

Claims

1. A monitoring assembly for use in a vehicle, comprising:

a monitor device changing the reflectance thereof in response to a control signal;

a first light sensor for receiving a first light from a first specified range, and outputting a first signal in response to the intensity of said first light;

a second light sensor for receiving a second light from a second specified range partially overlapping with said first specified range, and outputting a second signal in response to the intensity of said second light; and

a comparative controller in communication with said first light sensor and said second light sensor, receiving and operating said first signal and said second signals to obtain a first result, and asserting said control signal to adjust the reflectance of said monitor device according to said first result, wherein said comparative controller includes a comparator receiving said first signal and said second signal, comparing said first signal at a first time point and said first signal at a second time point to obtain a first light variation, comparing said second signal at said first time point and said second signal at said second time point to obtain a second light variation, and further comparing said first signal and said second signal at said second time point to obtain a light difference on a condition that said first light variation or said second light variation exceeds a first threshold value.

2. The monitoring assembly according to claim 1 wherein said monitor device is an electrochromic rearview mirror.

3. The monitoring assembly according to claim 2 wherein said first light sensor and said second light sensors are both mounted on said electrochromic rearview mirror facing inside the vehicle.

4. The monitoring assembly according to claim 2 wherein said comparative controller includes

a base discriminating circuit in communication with said comparator, comparing said light difference with a second threshold value to obtain said first result.

5. The monitoring assembly according to claim 4 wherein said comparative controller further includes:

a balance device receiving and comparing said first signal and said second signal in an initial mode to obtain a photoelectric response error; and

a multi-level driving circuit in communication with said base discriminating circuit and said balance device, differentially adjusting the reflectance of said electrochromic rearview mirror according to said first result and said photoelectric response error.

6. The monitoring assembly according to claim 5 wherein said multi-level driving circuit adjusts the reflectance of said electrochromic rearview mirror when said light difference is substantially unequal to said photoelectric response error, and said first result indicates the light difference is greater than said second threshold value.

7. The monitoring assembly according to claim 2 wherein said first light sensor and second light sensors are arranged on two corners of said electrochromic rearview mirror.

8. The monitoring assembly according to claim 2 wherein said electrochromic rearview mirror is selected from an interior rearview mirror, an exterior rearview mirror, and a combined interior and exterior mirror set.

9. The monitoring assembly according to claim 1 wherein said monitor device is a display.

10. The monitoring assembly according to claim 9 wherein said monitor device is a liquid crystal display.

11. An anti-glare rearview mirror assembly for use in a vehicle, comprising:

a first electrochromic rearview mirror changing the reflectance thereof in response to a first control signal;

a second electrochromic rearview mirror changing the reflectance thereof in response to a second control signal;

a first rearward light sensor disposed on said first electrochromic rearview mirror for receiving a first light, and outputting a first signal in response to the intensity of said first light;

a second light sensor disposed on said second electrochromic rearview mirror for receiving a second light, and outputting a second signal in response to the intensity of said second light; and

a comparative controller in communication with said first light sensor and said second light sensor, receiving and operating said first signal and said second signal to obtain a first result, and asserting either of said first control signal and said second control signal to adjust the reflectance of a corresponding one of said first electrochromic rearview mirror and said second electrochromic rearview mirror according to said first result, wherein said comparative controller includes a comparator receiving said first signal and said second signal, comparing said first signal at a first time point and said first signal at a second time point to obtain a first light variation, comparing said second signal at said first time point and said second signal at said second time point to obtain a second light variation, and further comparing said first signal and said second signal at said second time point to obtain a light difference on a condition that said first light variation or said second light variation exceeds a first threshold value.

12. The anti-glare rearview mirror assembly according to claim 11 wherein said first electrochromic rearview mirror and said second electrochromic rearview mirror are an interior and an exterior rearview mirrors changing colors thereof in response to said first control signal and said second control signal, respectively.

13. The anti-glare rearview mirror assembly according to claim 11 wherein said first electrochromic rearview mirror and second electrochromic rearview mirror are two exterior rearview mirrors changing colors thereof in response to said first control signal and said second control signal, respectively.

14. The anti-glare rearview mirror assembly according to claim 11 wherein said comparative controller includes

a base discriminating circuit in communication with said comparator, comparing said light difference with a second threshold value to obtain said first result.

15. The anti-glare rearview mirror assembly according to claim 11 wherein said comparative controller further includes:

a balance device receiving and comparing said first signal and said second signal in an initial mode to obtain a photoelectric response error; and

a multi-level driving circuit in communication with said base discriminating circuit and said balance device, differentially adjusting the reflectance of said electrochromic rearview mirror according to said first result and said photoelectric response error.

16. The anti-glare rearview mirror assembly according to claim 15 wherein said multi-level driving circuit adjusts the reflectance of said electrochromic rearview mirror when said light difference is substantially unequal to said photoelectric response error, and said first result indicates the light difference is greater than said second threshold value.

17. The anti-glare rearview mirror assembly according to claim 11 further comprising a third sensor disposed on said first electrochromic rearview mirror for receiving a third light, and outputting a third signal in response to the intensity of said third light.

18. The anti-glare rearview mirror assembly according to claim 17 further comprising:

a third electrochromic rearview mirror changing the reflectance thereof in response to a third control signal; and

a fourth sensor disposed on said third electrochromic rearview mirror of said vehicle for receiving a fourth light, and outputting a fourth signal in response to the intensity of said fourth light.

19. The anti-glare rearview mirror assembly according to claim 11 further comprising:

a third electrochromic rearview mirror changing the reflectance thereof in response to a third control signal; and

a third sensor disposed on said third electrochromic rearview mirror of said vehicle for receiving a third light, and outputting a third signal in response to the intensity of said third light.

20. A reflectance control method of a monitoring assembly, comprising steps of:

receiving a first rearward light from a first specified region and a second rearward light from a second specified region at a first time point;

receiving a third rearward light from said first specified region and a fourth rearward light from said second specified region at a second time point preceding said first time point;

comparing intensities of said first rearward light and said third rearward light to obtain a first light variation;

comparing intensities of said second rearward light and said fourth rearward light to obtain a second light variation;

comparing said first light variation and said second light variation with a first threshold value;

comparing intensities of said first rearward light and said second rearward light to obtain a light difference therebetween; and

adjusting the reflectance of a monitor device according to said light difference on a condition that said first light and/or said second light variation exceeds said first threshold value.

21. The method according to claim 20 further comprising a step of comparing said light difference with a photoelectric response error, and disabling said step of adjusting the reflectance of said monitor device when a difference of said light difference and said photoelectric response error is within a predetermined range.

22. The method according to claim 20 further comprising a step of comparing said intensities of said first rearward light and said second rearward light with a threshold value, and disabling said step of adjusting the reflectance of said monitor device when both of said intensities of said first rearward light and said second rearward lights are greater than said threshold value.

23. The method according to claim 20 wherein said step of adjusting the reflectance of said monitor device is performed on a condition that said light difference exceeds a second threshold value.

24. The method according to claim 20 wherein said monitor device is a liquid crystal display.

25. The method according to claim 20 wherein said monitor device is an anti-glare rearview mirror.

26. The method according to claim 25 wherein said monitor device includes an interior rearview mirror arranged inside a vehicle and two exterior rearview mirrors respectively arranged by two sides of said vehicle, and said anti-glare rearview mirror is said interior rearview mirror.

27. The method according to claim 26 further comprising a step of determining which one of said first rearward light and said second rearward light is larger, and further adjusting the reflectance of one of said exterior rearview mirrors, which is closer to said rearward light with larger intensity than to said rearward light with smaller intensity.

28. A reflectance control method of an anti-glare rearview mirror assembly, said anti-glare rearview mirror assembly comprising of a first rearview mirror, a second rearview mirror and a third rearview mirror, and said stepmethod comprising the steps of:

mounting a first light sensor, a second light sensor and a third light sensor on said first rearview mirror, said second rearview mirror and said third rearview mirror, respectively;

receiving a first rearward light, a second rearward light, and a third rearward light at a first time point;

receiving a fourth rearward light, a fifth rearward light, and a sixth rearward light at a second time point following said first time point;

comparing intensities of said first rearward light, said second rearward light and said third rearward light with said fourth rearward light, said fifth rearward light and said sixth rearward light, respectively, to obtain a first light difference, a second light difference and a third light difference;

comparing said first light difference, said second light difference and said third light difference with a threshold value; and

adjusting the reflectance of any of said first rearview mirror, said second rearview mirror and said third rearview mirror having said light difference thereof greater than said threshold value.

29. The method according to claim 28 wherein said step of adjusting reflectance is performed according to levels of said light differences.