LOCK-IN IMAGING SYSTEM

PROBLEM TO BE SOLVED: To perform recognition of a pedestrian buried in headlight in the nighttime photo-detection, image pickup, etc., of an object with weak light which is easy to be buried in noise with simple structure. SOLUTION: This lock-in imaging system is constituted by integrating a lock-in detecting function in charge feedback optical sensors in two-dimensional arrangement and sets a lock-in amplifier cycle by selecting one of a plurality of lock-in amplifier cycles preset in a lock-in amplifier cycle setting part. A pulse light source is flickered being synchronized with the set lock-in amplifier cycle. Light receiving quantity in odd-numbered frame received at a state that the pulse light source is lit is stored as a positive electric charge and light receiving quantity in even-numbered frames is stored as a negative electric charge. Only an object of image pickup is made into an image with satisfactory S/N by integrating the stored quantity of electric charge for over prescribed even-numbered frames.