Patent ID: 7733585

Claim:
A lens device for image magnification of a specimen, comprising: a control unit including a main circuit board; a tube assembly including a guide barrel disposed on said main circuit board, confining a barrel hole that extends along a barrel axis, and formed with a set of slots that extend parallel to the barrel axis, an outer tube including a tube body that is rotatably sleeved on said guide barrel and that has an inner tube surface, and a guiding portion that is formed on said inner tube surface of said tube body, and a lens holder including a holder body that is disposed movably in said barrel hole of said guide barrel and that has a set of projections that extend through said slots to engage said guiding portion, wherein rotation of said outer tube relative to said guide barrel results in said guiding portion driving said projections to result in movement of said lens holder in said guide barrel along the barrel axis; an image sensor disposed on and electrically coupled to said main circuit board, said image sensor being disposed in said guide barrel; an objective lens mounted to said lens holder and optically aligned with said image sensor; a light source coupled electrically to said main circuit board and operable to output light for illumination; and a detecting unit coupled to said main circuit board and generating a detector output indicating angular orientation of said outer tube relative to said main circuit board; said control unit being responsive to the detector output to control intensity of the light outputted by said light source according to the angular orientation of said outer tube.