| 摘要 |
A monochromator according to the present invention has an arm 1 rotatably mounted on a rotation shaft 3, and a diffraction grating 6 is fixed to the arm 1. The arm 1 is rotated by a linear motor 9 including a moving part 91 fixed to the arm 1 and a stator part 92 fixed to a base 2. The linear motor 9 is a voice-coil linear motor constructed to allow the arm 1 to rotate reciprocatively around the rotation shaft 3 within a preset angular rage. The absolute rotational position of the arm 1 is detected by a rotary encoder 7 including a crossbar 71 fixed to the arm 1 and a encoder block 72 fixed to the base 2. Based on the output signal of the rotary encoder 7, the linear motor 9 is controlled so that the moving part 92 rotates at a fixed angular speed around the rotation axis 3. Thus, the wavelength scanning is carried out at high speed, and sampling of monochromatic light having desired wavelengths is performed accurately. <IMAGE> |
