Patent ID: 7880800

Claim:
An auto focus system for moving a focusing lens of a photographing lens based on a contrast of an image of an object which is focused by the photographing lens, comprising: auto focus controlling means for automatically setting the focusing lens to a focus position; and speed indicating means for inputting an indication of a movement speed of the focusing lens, so that the auto focus controlling means causes the focusing lens to move at the movement speed indicated by the speed indicating means, wherein said auto focus controlling means provides an automatically setting mode for automatically setting a movement speed of the focusing lens in response to the setting of the photographing lens which at least includes a focal length or an aperture value; and a manually setting mode for setting a movement speed of the focusing lens to the movement speed indicated by the speed indicating means, wherein the speed indicating means inputs an indication of an amount of change with respect to the movement speed of the focusing lens which is set by the automatically setting mode, and in the manually setting mode, the auto focus controlling means sets the value obtained by adding the amount of change to the movement speed which is set by the automatically setting mode as a movement speed of the focusing lens.