초록 ▼

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 includ

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.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A vehicular electrochromic rearview mirror system, comprising:at least one electrochromic rearview mirror assembly comprising an electrochromic reflective element, wherein said ele

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A vehicular electrochromic rearview mirror system, comprising:at least one electrochromic rearview mirror assembly comprising an electrochromic reflective element, wherein said electrochromic reflective element assumes a partial reflectance level in response to a signal applied thereto;a drive circuit applying a drive signal to said electrochromic reflective element establishing a partial reflectance level thereof, said drive circuit including a digital controller and a variable source, said variable source controllably repetitively interrupting current through said variable source in response to said digital controller thereby providing a voltage reduced from a particular voltage level, said drive signal comprising said voltage reduced from said particular level; andwherein said variable source comprises an electronic switch, wherein said electronic switch is alternatingly driven and not driven according to a duty cycle by said digital controller, and wherein said drive circuit monitors voltage across said electrochromic reflective element and varies said duty cycle at least in part as a function of the voltage across said electrochromic cell.