Imaging apparatus having a solid state matrix-type imaging element and

Abstract

In an imaging apparatus capable of expanding a dynamic range image signals of different levels are read simultaneously from a solid-state element whose light-receiving surface is divided. Read 1/2 frame image signals are switched by a changeover switch circuit at intervals of a 1/2 frame time. One of two image signals of different levels supplied from the two outputs of the changeover switch circuit is delayed at a delay circuit. Further, those image signals are separated into r, g, and b components, and then undergo logarithmic conversion into image signals of multiple desired levels. The signals are digitized at an A/D converter and undergo operations at an adder, which adds while keeping their logarithmic characteristic, and at an inverse logarithmic converter. A luminance signal is obtained at a matrix circuit, and is converted into a logarithm at a logarithmic circuit. The lighting irregularity components of the resulting signal are suppressed. This signal is compressed, and the compressed signal is subtracted at a subtracter to obtain a compression coefficient, which is added to the digitized image signal from the A/D converter. Image signals of a wide dynamic range corrected at the inverse logarithmic converter are obtained for a single image at a TV rate on a real-time basis. Further, the control of exposure to the entire image and the expansion of the dynamic range are possible.