| 摘要 |
PURPOSE:To automatically correct wavelength shift, by correcting the slip of a motor by detecting a means to be detected (a slit) provided to the rotary part connected to the motor. CONSTITUTION:A disc 6 is fixed to the wavelength feed master screw 4 of a grating and slits are provided to the disc 6 along the circumference of the circle thereof at equal intervals. The interval between adjacent slits corresponds to n-numbers of the drive pulses of a stepping motor 5 when the disc 6 is rotated along with the master screw 4 by the motor 5, a detection pulse is outputted from a photo-interruptor 7 and subjected to adding or subtracting counting by a detection counter 12. A control circuit 8 multiplies the count value of the counter n-times to compare the n-times value with the count value of a motor counter 11 and, if both valves are coincided, the wavelength corresponding to the count value of the counter 11 is displayed by a display device 13 while, if not coincided, the wavelength based on the count value of the counter 11 to which correction corresponding to the difference of both valves is applied is displayed by the display device 13. Therefore, wavelength shift is automatically corrected. |
