Dissimilar endoscopes usable with a common control unit

An endoscope system comprising:

• an endoscope control unit provided with image signal generating means for signal processing an image pickup signal having fixed specifications from an endoscope to generate a standard image signal, and a main signal generating means for generating a main synchronizing signal for driving image pickup means provided on said endoscope;
• a first endoscope connectable to said endoscope control unit and provided with high resolution first image pickup means having a large number of pixels, and capable of picking up an image pickup signal having higher resolution than said image pickup signal having said fixed specifications;
• a second endoscope connectable to said endoscope control unit and provided with low resolution second image pickup means being miniaturized and capable of picking up an image pickup signal having a lower resolution than an image pickup signal of said fixed specifications;
• first signal rationalizing means for rationalizing a form of a signal exchanged between said first endoscope and said endoscope control unit, said first signal rationalizing means including a first subsidiary synchronizing signal generator circuit for detecting the phase of said main synchronizing signal generated from said main synchronizing signal generator circuit to generate a first subsidiary synchronizing signal which is synchronized with said main synchronizing signal, a first drive pulse generator circuit for signal processing said first subsidiary synchronizing signal which is generated from said first subsidiary synchronizing signal generator circuit to generate a first drive signal used for said high resolution first image pickup means, and two-line adding means for simultaneously reading and adding together two lines of the image pickup signal from said high resolution first image pickup means on the basis of said first subsidiary synchronizing signal to provide high-speed reading, said two-line adding means outputting an image pickup signal of said fixed specifications to said image signal generating means;
• and
• a second signal rationalizing means for rationalizing a form of a signal exchanged between said second endoscope and said endoscope control unit, said second signal rationalizing means including a second subsidiary synchronizing signal generator circuit for detecting the phase of said main synchronizing signal generated from said main synchronizing signal generator circuit to generate a second subsidiary synchronizing signal which is synchronized with said main synchronizing signal, a second drive pulse generator circuit for signal processing said second subsidiary synchronizing signal from said second subsidiary synchronizing signal generator circuit to generate a second drive signal used for said low resolution second image pickup means, and interpolation enlargement means for interpolation processing an image pickup signal from said low resolution second image pickup means on the basis of said second subsidiary synchronizing signal to provide enlargement of said image pickup signal, said interpolation enlargement means for outputting an image pickup signal of said fixed specifications to said image signal generating means.