Patent attributes
To provide an image pickup system having CCDs 25 driven at different frequencies respectively which can drive each CCD 25 with a predetermined frequency if a detachable camera head (or electronic endoscope) 28 is used and also can process a signal processing clock of a video processing circuit 29 with one type of clock. A drive signal of the predetermined frequency supplied to the CCD is produced via a generating circuit CXO 155 in the video processing circuit 29, a frequency dividing circuit 132 and a timing generator (T.G.) 131. A CCD signal outputted from the CCD 25 is inputted to a line memory 139 in a floating circuit 135. As a writing clock (WCK) of the line memory 139, the one which is divided in the frequency dividing circuit 132 to a frequency in accordance with the CCD 25 to be used is used, and as a reading clock (RCK), the one of one type of frequency is used without regard to the CCD 25 to be used. Hence, it is possible to perform the signal processing of a secondary circuit 136 of the line memory 139 and following ones always with a common generating clock.
