Control device for an electrically powered foldable rearview mirror for automobiles

An electrically powered foldable rearview mirror comprising

• a base,
• a shaft arranged on the base and having a shaft flange portion,
• a mirror body rotatable on the shaft between a folded position and an erected position,
• a frame mounted in the mirror body and having a root portion provided with a hole through which the shaft extends and a wing portion to support a mirror element;
• an electric driving means contained in the mirror body for rotating the mirror body and a speed reduction gear mechanism connected with the electric driving means and the mirror body, said electric driving means and said speed reducing gear mechanism being fixed to the frame root portion;
• rotation stop means for halting mirror body rotation at the folded position and at the erected position, said rotation stop means being arranged around the shaft between an upper surface of the shaft flange portion and the frame root portion;
• a gear box mounted on the frame root portion to surround the shaft and the speed reduction gear mechanism, said gear box including a vertical wall connected to the frame root portion and an outer plate engaged with an upper portion of the vertical wall and engaged with an upper portion of the shaft;
• a clutch gear engaged on the shaft to engage with an end gear of the speed reduction gear mechanism;
• and
• a control device comprising
• a switching circuit including means for connecting a power supply to said electric driving means to rotate the mirror body into the erected state and means for connecting a power supply to said electric driving means to rotate the mirror body into the folded state;
• a relay circuit connected electrically to the switching circuit and to the electric motor and including means for supplying and for cutting off an electric current from said power supply to said electric motor;
• and
• a package arranged on the outer plate of the gear box, said package including a relay control circuit comprising a resistance connected electrically with the electric motor so as to produce a voltage drop from the electric current supplied to the electric motor from the power supply;
• means for activating the relay circuit to cut off said electric current to said motor when said mirror body rotation is stopped by said rotation stop means or by an externally applied force on said mirror body;
• and means for determining when said mirror body rotation is stopped, wherein said means for activating the relay circuit and said means for determining when said mirror body rotation is stopped comprise a semiconductor device connected electrically in parallel with the resistance, said semiconductor device including means for detecting when said voltage drop is greater than a predetermined threshold voltage of the semiconductor device.