| 摘要 |
PROBLEM TO BE SOLVED: To keep high optical performance by calculating the data of correction position, where the fluctuation of position on an image forming plane can be corrected, based on temperature information. SOLUTION: By inputting output signals from temperature sensors 12 arranged around a fore ball 101 through a detection circuit 24 to a control circuit 13, a temperature T at the place where the temperature sensors 12 are installed is detected. The control circuit 13 is a microprocessor really and corresponding to the sampling frequency of microcomputer, the detected temperature is fetched into the microcomputer as data. By comparing the detected environmental temperature T(k) with a reference temperature T0, its differenceΔT=T(k)-T0 is calculated. A temperature correction coefficient CMRR and representative position data PRR of mobile lens group RR104 are read, the operation of PRRT =CMRR×ΔT+PRR is performed and the correction position data after the correction of RR104, namely, feed-out quantity PRRT is calculated. Based on these calculated data, a variator 102 and the RR104 are respectively driven. |
