Patent ID: 8050549
Filing Date: 2011-11-01
Classification: G03B

Abstract:
1. A method for controlling an auto macro function of a lens module, said lens module comprising an upper coupling element, a single spring and said single spring disposed under said upper coupling element, a magnet yoke disposed under said single spring, multiple magnets, a lens holder supporting a coil and a lens, and a lower coupling element, said coil having a first terminal connected to a power source, said method comprising steps of: providing a control switching module operated at either a first switching state or a second switching state, wherein said control switching module includes a current-limiting resistor and a transistor having a base and two terminals, and one of said two terminals of said transistor is connected to a second terminal of said coil in series; issuing a control signal to said control switching module; transmitting a constant current from said power source to said coil when said control switching module is operated at said first switching state in response to said control signal, wherein said magnets attached on said magnet yoke provide a permanent magnetic field, and said constant current passing through said coil causes a magnetic force to be generated on said coil while moving said lens holder toward said magnet yoke by a constant distance, so that said lens holder is sustained against said spring, and stopping transmitting said constant current from said power source to said coil when said control switching module is operated at said second switching state in response to said control signal, wherein a restoring force generated by said deformed spring causes said lens holder to return to its original position.