Illumination level measurement using a photodiode array

摘要

A photodiode matrix (1) has a set of address (L1,L2...) and read (F1,F2...) lines. The read lines drive integrating amplifiers (30). The current flow in the address lines is measured by circuitry (200) in series with the supply voltage (SVR). The current flowing in the read lines is similarly measured (300). Together these measurements give an absolute value for the level of illumination falling on the matrix.