Patent ID: 6364495
Filing Date: 2002-04-02
Classification: B60R

Abstract:
A back mirror comprising an automatic glare-proof function while having an EC mirror in which a light surrounding a vehicle and a light from the back of the vehicle are detected so as to change over between a glare-proof state and a glare-non-proof state of the EC mirror automatically in response to the results of the detection, said back mirror comprisinga daytime/nighttime deciding means including a first surrounding light sensor that detects a surrounding light of the vehicle and is driven by a voltage output from a DC power source, and detecting whether a current time is daytime or nighttime based on the result of the detection made by the first surrounding light sensor; a switching means turned on when the daytime/nighttime deciding means has decided that the current time is nighttime; a glare-proof/glare-non-proof deciding means including a second surrounding light sensor for detecting a light surrounding the vehicle and a backward light sensor for detecting a light from the back of the vehicle, both applied with a voltage output from the DC power source when the switching means has been turned on so as to decide whether the EC mirror is to be set to the glare-proof state or not based on the results of the detection by the second surrounding light sensor and the backward light sensor respectively; and a driving means applied with a voltage output from the DC power source when the switching means has been turned on, wherein a coloring and a discoloring of the EC mirror will be changed over in response to the result of the decision made by the glare-proof/glare-non-proof deciding means, and the first surrounding light sensor is composed of an element of which resistance value varies according to the brightness of the surrounding light, and the daytime/nighttime deciding means includes a series-connected circuit of the first surrounding light sensor and a resistor in which a voltage output from the DC power source is applied to both ends of the series-connected circuit so that the daytime/nighttime deciding means detects a voltage at a connection point between the surrounding light sensor and the resistor so as to decide whether the current time is daytime or nighttime.