Patent ID: 7027151
Filing Date: 2006-04-11
Classification: G01J

Abstract:
1. A spectrophotometer comprising: a spectroscope including a motor, a reduction device formed of a Harmonic Drive mechanism and connected to the motor to reduce rotation of the motor, and a wavelength dispersion element driven by the reduction device, a correction formula storing device for storing a correction formula expressing a cyclic error waveform of the reduction device, said correction formula including a linear binding of functions having a periodicity of 1/n of a cycle corresponding to one cycle on an input axis side of the reduction device, where n represents a natural number dependent on a structure of the reduction device, a coefficient acquiring device for calculating and storing at least one coefficient contained in the correction formula based on measured results of bright line spectrums, and a control device electrically connected to the reduction device, correction formula storing device and coefficient acquiring device for correcting a rotating angle corresponding to an objective wavelength in using the correction formula with the coefficients when the objective wavelength is set in an actual measurement and controlling the motor to obtain the corrected rotating angle.