초록 ▼

A technique for automatically focusing the lens of an electronic still camera employs a full frame image sensor 20 and a mechanical shutter 24. The image sensor 20 itself is operated first in a “fast flush”mode to focus a lens 22, and then in a normal readout mode to obtain the final still image. To

A technique for automatically focusing the lens of an electronic still camera employs a full frame image sensor 20 and a mechanical shutter 24. The image sensor 20 itself is operated first in a “fast flush”mode to focus a lens 22, and then in a normal readout mode to obtain the final still image. To focus the lens 22, the shutter 24 is opened, and an image is integrated on the sensor 20. The average contrast of a central region 66 of the image is used to determine how well the image is focused. The portion of the image surrounding the central region 66 is rapidly read out and discarded, using “fast flush”clocking where the vertical and horizontal registers are continuously clocked. The process is repeated numerous times with the shutter remaining open as the lens focus is adjusted until the maximum average contrast is obtained. At this point, the shutter is closed, and the entire sensor is cleared using “fast flush”clocking. The shutter is again opened to capture the final image, and closed while the final image is read out.

대표청구항 ▼

An electronic camera having an automatically-focused lens that images light through a shutter upon an image sensor during separate image focus and image capture cycles, the shutter operable to regulate light upon the sensor and the lens operable to focus an image based upon image data obtained from

An electronic camera having an automatically-focused lens that images light through a shutter upon an image sensor during separate image focus and image capture cycles, the shutter operable to regulate light upon the sensor and the lens operable to focus an image based upon image data obtained from the sensor during image focus cycles, the improvement wherein the image sensor is a full frame transfer image sensor in which image charge is incremented line-by-line through photosites on the sensor to an output section; and the shutter remains open during a plurality of image focus cycles while the lens is being focused, wherein consequent image smear is reduced to an acceptable level by transferring image charge from the sensor more rapidly during focusing than during image capture, and the shutter is closed in order to eliminate image smear before reading out an image after an image capture cycle.