Patent ID: 6307393
Filing Date: 2001-10-23
Classification: H04N

Abstract:
An apparatus for detecting defects in an imaging system including a solid-state image sensor having an image pickup area larger than an effective image pickup area, said imaging system being operative in a normal mode and a defect detection mode, the apparatus comprising:a timing generator producing first and second read pulses for reading out signal charges of first and second fields respectively from photo sensing elements disposed in the pixels of said solid-state image sensor;control means for controlling the timing of the production of the first and second read pulses from said timing generator; andmeans for detecting a defect while said imaging system is in said defect detection mode, wherein the signal charges of said first and second fields are stored for a predetermined storage period in said solid-state image sensor and the means for detecting a defect detects any defective pixel of said solid-state image sensor during a defect detection period by detecting the level of the signal charge in each pixel;wherein, when said imaging system is operating in said normal mode first read pulses and second read pulses are supplied to said image sensor at a predetermined periodic rate, and when said imaging system is operating in said defect detection mode read pulses are supplied to said image sensor such that a first read pulse is supplied from said timing generator to said solid-state image sensor for reading out and starting storage of the first-field signal charges for a first predetermined number of field periods and a second read pulse is supplied from said timing generator to said solid-state image sensor after a lapse of two fields from the start of the storage of the first-field signal charge for reading out and starting storage of the second-field signal charges for a second predetermined number of field periods.