Patent ID: 6618090
Filing Date: 2003-09-09
Classification: H04N

Abstract:
An electronic camera including an automatic exposure control apparatus comprising:a timing generator circuit for generating a readout pulse signal and a transfer signal at a predetermined timing; an imager that converts light from a subject passing through an image-capture lens to signal charges corresponding to the subject, the imager comprising a photoelectric conversion area and a vertical transfer area formed on a photoelectric conversion surface thereof, signal charges produced in the photoelectric conversion area being transferred to the vertical transfer area responsive to said readout pulse signal applied to said imager, the signal charges transferred to the vertical transfer area then being transferred to a horizontal transfer area responsive to said transfer signal, which is composed of a vertical signal and a horizontal signal, so as to issue an output signal through an output terminal provided on an end of the horizontal transfer area; an exposure operation/control unit that controls specific exposure controlling elements inclusive of the timing generator circuit and other predetermined circuits or mechanical elements provided in the electronic camera; wherein the exposure operation/control unit performs ON/OFF control of the imager through the timing generator circuit to apply the readout pulse signal to the imager at a predetermined timing to transfer the signal charges produced in the photoelectric conversion area to the vertical transfer area thereby transferring the signal charges and an intermixed smear component to the output terminal, when in a first operating state, and omitting the readout pulse signal to the imager to prevent signal charge produced in the photoelectric conversion area from being transferred to the transfer area thereby extracting only the smear component from the vertical transfer area at the output terminal when in a second operating state, the exposure operation/control unit performing a first integration operation upon the signal charges and intermixed smear component measuring a predetermined automatic exposure (AE) area set on the photoelectric conversion surface of the imager and obtained during said first operating state, and performing a second integration operation upon only the smear component measuring the same predetermined AE area and obtained during said second operating state, and then subtracting a result of the second integration from a result of the first integration to obtain an AE integration value containing almost no smear component to provide a proper operation for taking a picture.