Patent ID: 7146097

Claim:
A focusing device comprising: a lens; a lens moving mechanism for moving the lens in an optical-axis direction; a motor for driving the lens moving mechanisim; a lens holder for holding the lens; a guide cylinder fitted to the outside of the lens holder and moved by interlocking with the movement of the lens holder; and a rotor arranged outside the guide cylinder and rotating by the driving of the motor, wherein the lens moving mechanism includes a first guide portion for guiding the lens to move in the optical-axis direction by a first predetermined distance to a minute focusing region, wherein second guide portion for guiding the lens to minutely move in the minute focusing region by a second predetermined distance in the optical-axis direction, wherein the first guide portion is formed on the inner circumferential surface of the rotor, wherein the second guide portion is formed on the outer circumferential surface of the lens holder, wherein a guide protrusion engaged with the first guide portion is provided on the outer circumferential surface of the guide cylinder, wherein the guide protrusion is guided to the first guide portion in accordance with the rotation of the rotor to move the lens holder by the first predetermined distance in the optical-axis direction together with the guide cylinder, and wherein the lens holder minutely moves in the optical-axis direction by the second predetermined distance in accordance with the rotation of the rotor by the guiding of the second guide portion together with the guide cylinder.