Diffraction grating mounting device for scanning monochromator

Claim 1

In a diffraction grating mounting device for a scanning monochromator comprising: (a) a base member; (b) a diffraction grating; (c) a diffraction grating supporting axle which integrally supports the diffraction grating and is rotatably supported by the base member; (d) a first arm fixed to the diffraction grating supporting axle at right angles thereto; (e) a second arm swingably supported on the base member in a uniplanar relation with the first arm; (f) a link member connecting the first and the second arms at points equidistant from the rotational centers of the first and second arms, respectively, the distance between the points being equal to that between the rotational centers of the first and second arms; (g) a cam follower axle fixed to the link member; (h) a cam; (i) a motor for driving the cam; and (j) means for biasing the link member of the first and second arms so as to make the cam follower axle contact said cam; the diffraction grating mounting device wherein said cam follower axle is fixed to said link member at right angles thereto and is located in a plane parallel to the plane formed by said first and second arms, said cam has a linear driving portion, and the rotational position of said cam is adjustable in a direction parallel to a line connecting the points at which said link member is connected to said first and second arms.