| 摘要 |
PURPOSE:To prevent the mirror angle detection from generating an error by fitting a variable inductor to an expansion mechanism portion changing the mirror angle. CONSTITUTION:A mirror holder 12 and a housing 13 are connected together with expansion coupling means 18, 19. These expansion coupling means 18, 19 are located respectively on lines at a right angle to each other passing through a receptacle 15 which is a rotation fulcrum. The inductance value of a coil 36 is increased as a male screw 22 is inserted into the coil and decreased as the male scre 22 extracted from the coil 36. Accordingly, the coil 36 works as a variable inductor, and the angular position of a mirror 11 can be known by measuring the inductance value of the coil 36. |
