| 摘要 |
PURPOSE:To use a driving circuit in common and to drive a room mirror and side mirror properly in accordance with an environmental temperature by detecting temperatures near the room mirror and the side mirrors and reducing a driving voltage to impress the reduced voltage to the 1st and 2nd transmissivity changing means. CONSTITUTION:Liquid crystal elements 21-23 fitted to the room mirror 1 and the side mirrors 2, 3 are thermistors having positive temperature characteristics changing respective resistance values in accordance with respective temperatures. A voltage control circuit 14 boosts a battery voltage to form a voltage necessary for the driving of the liquid crystal elements 21-23. An oscillation circuit 15 receives the supply of a stabilized voltage from a stabilized power supply circuit 13 to execute oscillation operation and generates an oscillation signal having a prescribed frequency. An antidazzle detecting circuit 16 detects the intensity of the rays of light incident upon the room mirror 1, and when the intensity is prescribed level or more, the necessity of flare shielding is detected. A modulator 17 inputs a DC voltage outputted from a voltage control circuit 14, modulates the input voltage at the frequency of the oscillation signal outputted from the circuit 15 and generates a driving voltage for driving the liquid crystal elements. |
