Monochromator

Abstract

In a monochromator including a light dispersing element rotatable about an axis, a linear motor for rotating the light dispersing element around the axis, an encoder for generating a signal representing a rotational position of the light dispersing element, and a linear motor controller for detecting the rotational position of the light dispersing element based on the signal generated by the encoder, the inventive monochromator is characterized in that the signal generated by the encoder has a waveform including no flat portion. That is, the strength of the signal must change if the rotational position of the light dispersing element changes even slightly. Using a linear motor as a driving unit for the light dispersing element, the monochromator of the present invention can rotate the light dispersing element constantly with a stable speed even at high speed. And using such an encoder, the detecting accuracy of the rotational position of the light dispersing element is much improved compared to conventional ones. Thus a spectrophotometer using the inventive monochromator has a better efficiency and accuracy both in the wavelength scanning analysis and in the time course analysis.

Dependencies are inferred from the claim text.