Patent ID: 7626631
Filing Date: 2009-12-01
Classification: G02B,G03B,H04N

Abstract:
1. A focus control method of acquiring focus information a plurality of times while moving a focus lens, and determining an in-focus position on the basis of the acquired focus information comprising: a decision step determined by a control unit of, before acquiring focus information, deciding on the basis of a focus lens position whether the focus lens is to be moved toward an infinite end or a closest end; a focus information acquisition step determined by a control unit of acquiring the focus information while moving the focus lens in a direction decided in the decision step at a first predetermined velocity; a determination step determined by a control unit of determining whether the focus lens has passed an in-focus position or not on the basis of the focus information acquired in the focus information acquisition step; and a focusing step determined by a control unit of stopping moving the focus lens and starting moving the focus lens from the stop position in a direction reverse to the moved direction of the focus lens in the focus information acquisition step at a second predetermined velocity which is slower than said first predetermined velocity while maintaining timing of acquiring the focus information, wherein, in the focusing step, if it is determined that the focus lens has passed the in-focus position while moving toward the infinite end, the focus lens is immediately stopped, and if it is determined that the focus lens has passed the in-focus position while moving toward the closest end, the focus lens is stopped when the focus lens reaches the closest end.