Method and device for controlling auto micro function of lens module

A method for controlling an auto macro function of a lens module, said lens module comprising a magnet yoke, multiple magnets attached on said magnet yoke, a single spring disposed above said magnet yoke and a lens holder supporting a coil and a lens, said magnets axially surrounding said coil and being separated from said coil by a gap, said method comprising steps of:

• connecting a power source with a first terminal of said coil;
• connecting a control switching module to a second terminal of said coil and a ground terminal such that said power source, said coil, said control switching module and said ground terminal are connected in series, wherein said control switching module is operated at either a first switching state or a second switching state;
• issuing a control signal having a first signal state and a second signal state to said control switching module;
• and
• 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 at said first signal state, wherein said magnets attached on said magnet yoke provide a permanent magnetic field, and said 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 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 at said second signal state, wherein a restoring force generated by said deformed spring causes said lens holder to return to its original position.

A device for controlling an auto macro function of a lens module, said lens module comprising a magnet yoke, multiple magnets attached on said magnet yoke, a single spring disposed above said magnet yoke and a lens holder supporting a coil and a lens, said magnets axially surrounding said coil and being separated from said coil by a gap, said device comprising:

• a power source connected with a first terminal of said coil;
• a control switching module operated at either a first switching state or a second switching state, wherein said control switching module is connected to a second terminal of said coil and a ground terminal such that said power source, said coil, said control switching module and said ground terminal are connected in series;
• and
• a micro processor for issuing a control signal having a first signal state and a second signal state to said control switching module, wherein said magnets attached on said magnet yoke provide a permanent magnetic field, a constant current is transmitted 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 at said first signal state, 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 sustained against said spring, wherein said power source stops transmitting said constant current to said coil when said control switching module is operated at said second switching state in response to said control signal at said second signal state, so that a restoring force generated by said deformed spring causes said lens holder to return to its original position.