Image-sensing apparatus having a zoom lens system that folds an optical path

A camera comprising:

• an image-sensing apparatus for outputting an electric image signal representing an image of an object,
• wherein the image-sensing apparatus comprises:
• a zoom lens system for forming an optical image of an object with variable magnification, the zoom lens system including a plurality of lens units and achieving zooming by varying distances between the lens units;
• and
• an image sensor for converting the optical image formed by the zoom lens system into an electrical signal,
• the zoom lens system comprising, from an object side thereof:
• a first lens unit having a positive optical power and including a reflective member for turning an optical path, the first lens unit being kept stationary relative to the image sensor during zooming;
• a second lens unit disposed on an image side of the first lens unit and having a negative optical power, the second lens unit being moved relative to the image sensor during zooming;
• a third lens unit disposed on an image side of the second lens unit and having a positive optical power, the third lens unit being moved relative to the image sensor during zooming;
• and
• a fourth lens unit disposed on an image side of the third lens unit and having a positive optical power,
• wherein the zoom lens system fulfills the following conditions:
• 1.0<D/fW<3.0;
• and
• −8<fa/fW<−3
• where
• D represents an axial distance from a most object-side surface of the first lens unit to the reflective surface of the reflective member;
• fa represents a composite focal length of all optical elements disposed on an object side of the reflective member within the first lens unit;
• and
• fW represents a focal length of the zoom lens system as a whole at an wide-angle end.