Patent ID: 7679849

Claim:
A lens unit comprising: a lens barrel for receiving at least one lens; a housing for receiving the lens barrel; a motor arranged to displace the lens barrel between an initial position and a maximum displacement, wherein the displacement of a lens barrel is proportional to the level of an electrical signal applied to the motor when the electrical signal is between first and second levels, the first level corresponding to a level for starting movement of the lens barrel from the initial position and the second level corresponding to a level for bringing the lens barrel to the maximum displacement; a first conductor fixed to the lens barrel and arranged to make electrical contact with a second conductor fixed to the housing when said lens barrel is at one of said initial position and said maximum displacement; the first and second conductor each having a conductive surface; and a processor arranged to detect a change in the contact situation between the first and second conductive surfaces, to determine one of said first and second levels based on level of the electrical signal at the time of the change and to generate, based on said determined level, a level of said electrical signal for a desired displacement.