US 6,547,404 B2Granted

Digital electrochromic mirror system

AssigneeDonnelly Corporation

InventorKenneth L. Schierbeek

Life of this patent

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Abstract

An electrochromic rearview mirror system for a vehicle includes an electrochromic reflective element having an electrochromic cell, wherein the reflective element colors to a partial reflectance level in response to a drive signal applied to the cell. The rearview mirror assembly additionally includes a drive circuit which applies a pulsed drive signal to the electrochromic cell in order to establish the partial reflectance level of the reflective element. The drive circuit controls the partial reflectance level as a function of the duty cycle of the pulsed drive signal, which has a pulse repetition rate of at least approximately 10 cycles per second and preferably at least approximately 20 cycles per second. The drive circuit additionally adjusts the amplitude of the pulses as a function of the voltage developed across the electrochromic cell.

Claims29

Dependent claims

A vehicular digital electrochromic mirror system, comprising:

an interior mirror assembly and at least one exterior mirror assembly, said interior mirror assembly comprising an interior electrochromic reflective element and a control, said at least one exterior mirror assembly comprising an exterior electrochromic reflective element;
said control comprising at least one light sensor and a microcomputer, said microcomputer establishing an interior reflectance value established by a first pulse-width modulated signal for said interior reflective element and an exterior reflectance value established by a second pulse-width modulated signal for said exterior reflective element, said interior reflective element achieving a partial reflectance level in response to the interior reflectance value, said exterior reflectance element achieving a partial reflectance level in response to the exterior reflectance value;
a vehicle bus communicating the exterior reflectance value to said exterior reflective element;
said interior mirror assembly comprising at least one additional accessory;
and
said first and second pulse-width-modulated signals determined by:
PWM %=G(Cs−V)
where
PWM % is a value of the respective one of said first and second pulse-width-modulated signals expressed as a percentage,
G is a constant,
Cs is a voltage at which the respective one of said interior and exterior reflective elements begins coloration, and
V is a value of an output of said at least one light sensor.

9 more elements

A vehicular digital electrochromic mirror system, comprising:

an interior mirror assembly comprising an interior electrochromic reflective element and a control, a driver side exterior mirror assembly comprising a driver side exterior electrochromic reflective element and a passenger side exterior mirror assembly comprising a passenger side exterior electrochromic reflective element;
said control comprising at least one light sensor and a microcomputer, said microcomputer establishing an interior reflectance value established by a first pulse-width modulated signal for said interior reflective element, a driver side exterior reflectance value established by a second pulse-width modulated signal for said driver side exterior reflective element, and a passenger side exterior reflectance value established by a third pulse-width modulated signal for said passenger side exterior reflective element, said interior reflective element achieving a partial reflectance level in response to the interior reflectance value, said driver side exterior reflectance element achieving a partial reflectance level in response to the driver side exterior reflectance value, and said passenger side exterior reflective element achieving a partial reflectance level in response to the passenger side reflectance value;
a vehicle bus communicating the driver side exterior reflectance value to said driver side exterior reflective element and the passenger side exterior reflectance value to said passenger side exterior reflective element;
said interior mirror assembly comprising at least one additional accessory;
and
said first and second pulse-width-modulated signals determined by:
PWM %=G(Cs−V)
where
PWM % is a value of the respective one of said first, second and third pulse-width-modulated signals expressed as a percentage,
G is a constant,
Cs is a voltage at which the respective one of said interior, driver side exterior and passenger side exterior reflective elements begins coloration, and
V is a value of an output of said at least one light sensor.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/952,693Filed 12 Sep 2001 · division
Priority: 2 Apr 1997
Published: US 2002/0030891 A114 Mar 2002
Granted: 15 Apr 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification2 codes

B60R 1/088
Anti-glare mirrors, e.g. "day-night" mirrors: using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or…
B60R
Vehicle fittings and parts

Family

Application08/832,380Parent of this continuation · filed 2 Apr 1997
Application09/533,260Parent of this division · filed 20 Mar 2000
US 2002/0030891 A1Pre-grant publication · published 14 Mar 2002
US 6,305,807 B1Parent of this division
Application09/533,260Parent of this continuation
US 6,089,721 AParent of this continuation
US 2001/0028504 A1Published application
US 6,547,404 B2This patent

From the US filing history. Foreign family members aren’t listed.