Small camera optical system

PURPOSE: A small-sized camera optic system is provided to increase productivity by using conventional lenses, simplifying an assembling process, and minimizing a tolerance in the assembling process. CONSTITUTION: An image sensing chip(42) is installed on a substrate(40) in order to sense an image of a subject. A lens system(50) is used for focusing the image of the subject on an image sensing chip. A barrel(52) is used for supporting the lens system, aligning the lens system and the image sensing chip on the same axis, and separating the lens system and the image sensing chip from each other. A housing(54) is used for supporting the barrel and is coupled to the substrate. A bottom end of the barrel is in contact with a predetermined region of a surface of the image sensing chip.