Patent ID: 8011087

Claim:
A method for assembling a lens module with an image sensor, the lens module comprising a lens barrel and at least one lens received in the lens barrel, the method comprising: providing a holder comprising a first receiving space for receiving the lens barrel and a second receiving space for receiving the image sensor; disposing the image sensor in the second receiving space; locating the lens barrel at a first position in the first receiving space; providing a clamp having a light source for generating a light beam; casting the light beam on the lens module to allow the lens module to converge the light beam into a light spot on the image sensor; determining if the light spot is at its smallest to determine if a distance between the lens module at the first position and the image sensor is equal to a focal length of the lens module; moving the lens module to a second position in the first receiving space of the holder to achieve a predetermined distance from the first position; and positioning the lens module at the second position.