Electronic camera with rapid automatic focus of an image upon a progressive scan image sensor

An electronic camera having an automatically focused lens, the lens operable to focus an image based on image data electronically obtained by the camera, the camera comprising:

• an image sensor comprising a two-dimensional array of photosites arranged in lines and columns, a plurality of vertical registers adjacent photosite columns for transferring lines of image charge from the photosites to a horizontal register for readout as image data, and a charge drain interposed between the output of the vertical registers and the horizontal register for eliminating complete lines of image charge at a time from the image sensor;
• a timing and control section for controlling the charge drain so as to eliminate at least one line of image charge from a central area of the image sensor for every one or more consecutive lines of image charge that are transferred from the central area to the horizontal register for readout, thereby generating a pattern of transferred lines suitable for focus determination;
• and
• a processor generating a focus adjustment signal based on the transferred lines from the central area.

An electronic camera having an automatically focused lens, the lens operable to focus an image data electronically obtained by the camera, the camera comprising:

• a progressive scan image sensor capable of producing an entire image in a single scan in response to clocking signals, said image sensor comprising a two-dimensional array of photosites arranged in lines and columns, a plurality of vertical registers adjacent photosite columns for transferring lines of image charge from the photosites to a horizontal register for readout, and a fast dump structure interposed between the output of the vertical registers and the horizontal register for dumping complete lines of image charge at a time from the image sensor;
• a timing and control section for producing clocking signals to read out the entire array of photosites in a single scan, said timing and control section further enabling the fast dump structure to dump at least one line of image charge from a central area of the image sensor utilized for autofocus for every one or more lines of image charge that are transferred from the central area to the horizontal register for readout, thereby generating a pattern of lines suitable for focus determination;
• and
• a processor for generating a focus adjustment signal based on the transferred lines from the central area.