| 摘要 |
PROBLEM TO BE SOLVED: To obtain a proper video signal by changing a mixture ratio of a mean value of video signals and a peak value corresponding to ON/OFF of a microscope lighting so as to control automatic iris thereby attaining proper automatic iris control. SOLUTION: A CCD 13 processes an image made incident onto a camera head 12 through an adaptor lens 11 into a video signal, a correlation double sampling circuit(CDS) 15 applies prescribed signal processing to the video signal and gives the resulting signal to a CCU 17. An AGC 18 adjusts the level of the signal, and gives its output to a video process 19, from which a luminance signal and a chrominance signal are obtained and which detects a mean value and a peak value and provides each output to a CPU 22. An iris of the CPU 22 mixing the mean value and the peak value at a prescribed ratio supplies a signal to control a shutter speed of the CCD 13 to a timing generator(TG) 14 of the camera head 12 corresponding to a value required when the microscope lighting is ON or OFF so as to adjust the amplification factor of the AGC 18 as required. |
