| 摘要 |
PURPOSE:To reduce the cost required for adjustment and make a lens unit compact by finding the movement quantity of a focusing lens group from a stored value and the movement quantity of an image formation point per unit movement quantity of the focusing lens group. CONSTITUTION:A 1st storage means 1 is stored with the quantity DELTABf of deviation of the image formation point from a film plane (quantity of deviation at wide-angle end or telephoto end) due to variance in lens assembly, lens component size, or refractive index among lens materials. An arithmetic means 1 calculates the correction movement quantity of a focusing point lens group from the value stored in the 1st storage means and the movement quantity of the image formation point per unit movement quantity of the focusing lens group. A lens driving means 5 drives the focusing lens group according to the final movement quantity obtained by adding the correction movement quantity of the focusing lens group found by the arithmetic to the movement quantity of the focusing lens group calculated from a focusing value obtained by a non- TTL type range finding means. Consequently, the deviation of the image formation point from the film plane which is caused at the time of the manufacture and assembly of components is easily corrected. |
