METHOD AND APPARATUS FOR SENSING RADIATION AND PROVIDING ELECTRICAL READOUT

摘要

A substrate of semiconductor material of one conductivity type having a plurality of storage sites for storage of radiation generated minority carriers therein are arranged in a plurality of rows and columns. Each of the storage sites includes a row-oriented and a column-oriented conductor-insulator-semiconductor capacitive cell which are arranged so that the depletion regions formed therein in response to application of appropriate voltages in circuit therewith are closely coupled to permit charge stored therein to flow between the cells. Each of the row-oriented conducting members of a row of sites are connected to a respective row line. Each of the column-oriented conducting members of a column of sites are connected to a respective column line. Selective read out of charge stored in a row of sites is accomplished by changing the potential on the row line to cause flow of charge stored in the row-oriented storage elements thereof to flow into the column-oriented storage elements thereof. The read out of charge stored in column-oriented elements is accomplished by changing the potential on each of the column lines in turn to cause injection of carriers stored therein in turn into the substrate. Each such injection produces a respective current flow in circuit with the substrate which is sensed across an integrating capacitance which includes the inherent capacitance of the conducting members in relation to the substrate and the row and column lines of the array. Means are provided for periodically sampling the variation in voltage developed on the integrating capacitance to provide an electrical output varying in time in accordance with the variation in amplitude of the sampled voltages.