Control circuit, in particular for dimming an EC mirror glass of a rearview mirror of a motor vehicle

• US 20050270649A1
• Filed: 06/03/2005
• Published: 12/08/2005
• Est. Priority Date: 06/05/2004
• Status: Abandoned Application

• Current Assignee: Schefenacker Vision Systems Germany GmbH
• Original Assignee: Schefenacker Vision Systems Germany GmbH
• Inventors: Herrler, Manfred, Thiel, Rolf
• Application Number:
  US11/144,457
• Publication Number:
  US 20050270649A1
• Time in Patent Office: Days
• US Class Current: 359/603
• CPC Class Codes: B60R 1/08 involving special optical features, e.g. avoiding blind spots , e.g. convex mirrors; Side-by-side associations of rear-view and other mirrors B60R1/025, B60R1/10 take precedence
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors

Abstract

A control circuit having particular application in dimming an EC (Electrochromic) mirror glass of a rearview mirror of a motor vehicle. Light flux from headlight glare of vehicles traveling behind is received by one conductor and filtered whereas light flux from the ambient light is received by a second conductor and filtered in a way that complements the first filtering. This allows a single sensor to be used to sense both the ambient light and the glare light which enables simpler control of the dimming function.

Claims

1. Control circuit for dimming an EC mirror glass of a rearview mirror of a motor vehicle, said control circuit comprising a sensor which produces a signal as a function of supplied luminous fluxes, wherein the control circuit has at least one light conductor, whose light receiving side is preceded by a colour filter and which is arranged to supply a filtered luminous flux to the sensor, which is constructed as a colour sensor.

2. A control circuit according to claim 1, wherein the control circuit has at least one further light conductor, whose light receiving side is preceded by a further colour filter and which is arranged to supply a second filtered luminous flux to the colour sensor.

3. A control circuit, according to claim 2, wherein the colour filters block different wavelengths of light.

4. A control circuit according to claim 1, wherein the colour filters separate the spectral ranges of the luminous flux.

5. A control circuit according to claim 1, wherein there are two light conductors in the region before the colour sensor that are combined into one light conductor.

6. A control circuit according to claim 1, wherein the colour sensor is an RGB sensor.

7. A control circuit according to claim 1, wherein the colour sensor is an X3 CMOS image converter.

8. A mirror for a motor vehicle comprising the control circuit of any one of the preceding claims.

9. A mirror according to claim 8, wherein said at least one light conductor is arranged so that, in use, the received luminous flux is produced by the glare of vehicles travelling behind.

10. A mirror according to claim 8, wherein said further light conductor is arranged so that, in use, the received luminous flux is produced by the ambient light.

11. A mirror according to claim 8, wherein the light receiving side of the light conductors is constructed and/or arranged so that only light of the respective luminous flux enters the respective light conductor.

12. A method of dimming an EC mirror glass, said method comprising:

receiving a first luminous flux;

filtering said first flux;

sensing the colour of said filtered first flux and using the sensed colour to control dimming of the mirror glass.

13. A method according to claim 12, further comprising:

receiving a second luminous flux;

filtering said second flux;

sensing the colour of said filtered second flux and using also this sensed colour to control dimming.

14. A method according to claim 13, wherein said filtered first flux and filtered second flux are sensed by one and the same sensor.

15. A method according to claim 13, wherein said first flux is filtered so as to allow through colour(s) that are blocked when said second flux is filtered.

16. A method according to claim 13, wherein said second flux is ambient light.

17. A method according to claim 12, wherein said first flux is glare from vehicles traveling behind.