Focusing device

• Main Authors: Omata, Kyoichi, Miyano, Toshiki, Kiri, Manabu
• Format: Patent
• Language: English
• Published: 27.08.2002

1. Field of the Invention A focusing device includes a movable focusing lens adapted to be moved to different positions, a conversion element for converting light incident on and transmitted through the focusing lens into a signal, and a lens driving mechanism for moving the focusing lens. The focusing device further includes a focus evaluation value calculation unit for calculating a focus evaluation value for each position of the focusing lens based on the signal from the conversion element, and a lens position specifying unit for specifying a position of the focusing lens causing a maximum focus evaluation value as an in-focus lens position. The lens driving mechanism moves the focusing lens in response to the in-focus lens position specified by the lens position specifying unit. The focus evaluation value calculation unit, in response to a plurality of observation areas, calculates a focus evaluation value through addition of partial focus evaluation values obtained for the respective observation areas, and weights the partial focus evaluation value for at least one of the plurality of observation areas on the basis of said signal to position the focusing lens.