| 摘要 |
PURPOSE:To reduce a temperature variation and a secular change by using a combination of switches in order to detect a direction of an optical axis, and using a motor provided with a field winding of a forward rotation and a backward rotation. CONSTITUTION:In case a load is applied to the rear part of a vehicle, a selecting switch 6 is switched by selecting a scale in accordance with a degree of the load in order to prevent an optical axis of a head lamp from turning upward. When ''0'' is switched to ''1'', a + power source passes through reverse current preventing diodes 2 and 8 from a terminal 1 of the selecting switch, and it is connected to a forward rotation (backward rotation) field winding of a right motor 3 and a left motor 9 through switches B and B', therefore, right and left motors rotate forward (backward), and the optical axis is varied in the lower direction. A slide contact of optical axis detecting switches 1 and 7 moves to a position ''1'' from a position ''0'', and when it reaches ''1'', switches B and B' become off, no current flows to motors 3 and 9, and they stop. However the selecting switch may be switched, the optical axis is varied to a position corresponding to a switching scale of the selecting switch in the same way. |
