Abstract: A system is provided that measures the delay time of a first timing signal transmitted from a control unit to an imager and back to a phase detector. The phase detector also receives a second timing signal that is used as a reference to measure against the received/delayed first timing signal. Based on the phase detection, the system will retard or advance the first timing signal to compensate for the phase shift.

Abstract: A system is provided that measures the delay time of a first timing signal transmitted from a control unit to an imager and back to a phase detector. The phase detector also receives a second timing signal that is used as a reference to measure against the received/delayed first timing signal. Based on the phase detection, the system will retard or advance the first timing signal to compensate for the phase shift.

Abstract: A method and apparatus for automatically adjusting the exposure of video images of the type that are commonly generated during endoscopic examination of tissue. The output of a video amplifier is detected and compared with an ideal value. A corresponding adjustment of amplifier gain is determined and such adjustment compared with a predetermined optimum range of amplifier gain. In the event that the calculated adjustment lies within such optimum range, the gain of the amplifier is adjusted accordingly. In the event that the optimum range is exceeded by the absolute value of the calculated adjustment, the exposure time of the camera sensor and the gain of the amplifier are adjusted in opposite senses whereby the amplifier is continuously operated within its optimum range.