SOLID STATE IMAGE PICKUP DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a solid state image pickup device capable of automatically switching the linear transformation operation and logarithmic transformation operation of an electric signal corresponding to incident light upon a solid state image pickup element in accordance with the brightness of a subject whose image is to be picked up. SOLUTION: When the luminance of a subject detected by a detection element 4 is larger than a certain fixed value (e.g. 700 cd/m2), a switching judgment circuit 5 judges that an area sensor (solid state image pickup element) 3 is allowed to execute logarithmic transformation operation. A switching signal is sent from a switching signal generation circuit 6 on the basis of the judgment of the circuit 5 and the area sensor 3 executes the logarithmic transformation operation. When the luminance of the subject is smaller than the fixed value (e.g. 700 cd/m2), the circuit 5 judges that the sensor 3 is allowed to execute linear transformation operation. Thereby a switching signal is sent form the circuit 6 on the basis of the judgment of the circuit 5 and the sensor 3 executes the linear transformation operation.