Mobile lens unit with detection device
AssigneeSTMicroelectronics (Grenoble) SAS
InventorTarek Lule
Life of this patent
Estimating the term…
Abstract
A lens unit includes a lens barrel for receiving at least one lens and a motor arranged to displace the lens barrel between various positions. Displacement of the lens barrel is proportional to an electrical signal applied to the motor. A first conductor is fixed to the lens barrel and is arranged to make electrical contact with a second conductor when the lens barrel is at an initial position. A processor is arranged to detect a change in the electrical contact, to determine an electrical signal at the time of the change and to generate an electrical signal corresponding to the desired displacement.
Claims14
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.
A method of determining a level of an electrical signal to be applied to a motor to move a lens barrel to a certain position, wherein the displacement of the 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 an initial position and the second level corresponding to a level for bringing the lens barrel to a maximum displacement, and wherein a first conductor is 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 the initial position and the maximum displacement the method comprising:
- increasing the level of the electrical signal applied to said motor;
- detecting a change in said contact situation between said first and second conductors and determining one of the first and second levels based on the level of the electrical signal at the time of the change;
- and
- generating said level of said electrical signal to be applied to said motor for a desired displacement based on the determined level of said electrical signal.
Dependencies are inferred from the claim text.