Patent ID: 6784938
Filing Date: 2004-08-31
Classification: H04N

Abstract:
An electronic camera, comprising:a solid-state imaging device having a condenser micro-lens opposed to a light receptor for recording an image, said solid-state imaging device having a sensitivity parameter that varies with f-number settings of the electronic camera; a diaphragm having a diameter which is variable in relation to a plurality of f-numbers for controlling exposure of light to said solid-state imaging device; a zoom lens which can be driven between a telephoto position and a wide-angle position; a zoom lens position detector for detecting position information of said zoom lens; a memory for storing either data items of outputs of said solid-state imaging device which are associated with said plurality of f-numbers and obtained when said zoom lens is positioned at said telephoto position and said wide-angle position, or data items of ratios of the outputs, both said data items reflecting variations of the sensitivity parameter relative to the f-number settings; an exposure controller for calculating an exposure time according to an output of said solid-state imaging device associated with a given f-number, and for controlling exposure of light to said solid-state imaging device through said diaphragm; a linear interpolator that serves to obtain outputs of the solid-state imaging device or ratios of the outputs relative to a zoom position intermediate the telephoto position and wide-angle position, based on data stored in the memory; a correcting algorithm for detecting an output of said solid-state imaging device or a ratio of the output according to position information of said zoom lens which is detected by said zoom lens position detector and according to the data items stored in said memory during recording of said image, and for correcting the exposure time calculated by said exposure controller according to an output of said solid-state imaging device or to the ratio of the output; and a calculator that calculates a sensitivity ratio (SPn) for a zoom position (ZP), taking into consideration a telephoto position (ZT) and a wide-angle position (ZW) and STn and SWn are sensitivity ratios associated with F-numbers according to the expression: SPn=STn+(SWnâˆ’STn)(ZPâˆ’ZT)/(ZWâˆ’ZT).