Electronic device with camera and fingerprint security function

1. A method of performing a fingerprint security function in an electronic device having a camera unit, comprising:

adjusting a focus of a lens in the camera unit to a first focus level when a control signal set indicates a normal photograph mode;

adjusting the focus of the lens in the camera unit to a second focus level different from the first focus level when the control signal set indicates a fingerprint photograph mode;

capturing a plurality of fingerprint images with the camera unit when the lens is set to a plurality of second focus levels; and

generating an enhanced fingerprint image with more uniform focus and brightness than said plurality of fingerprint images using said plurality of fingerprint images.

2. The method of claim 1 , further comprising:

capturing a user-determined image with the camera unit when the lens is set to the first focus level.

3. The method of claim 1 , further comprising:

extracting and storing characteristics information of the enhanced fingerprint image in a memory when the control signal set indicates registration of a user.

4. The method of claim 1 , further comprising:

extracting and comparing characteristics information of the enhanced fingerprint image with registered characteristics information from a memory when the control signal set indicates authentication of a user.

5. The method of claim 1 , further comprising:

emitting light toward a fingerprint location when the control signal set indicates the fingerprint photograph mode.

6. The method of claim 5 , further comprising:

turning off the light toward the fingerprint location when the control signal set indicates the normal photograph mode.

7. The method of claim 1 , wherein the electronic device is a mobile phone.

8. The method of claim 1 , further comprising:

moving the lens to a first focal position when the control signal set indicates the normal photograph mode; and

moving the lens to a second focal position when the control signal set indicates the fingerprint photograph mode.

9. The method of claim 1 , further comprising:

biasing the lens with a first voltage to set the lens to have a first focal thickness when the control signal set indicates the normal photograph mode; and

biasing the lens with a second voltage to set the lens to have a second focal thickness when the control signal set indicates the fingerprint photograph mode.

10. An electronic device, comprising:

a camera unit with a lens that is used to capture images;

a data processor; and

a memory having sequences of instructions stored thereon, wherein execution of the sequences of instructions by the data processor causes the data processor to perform the steps of:

receiving a control signal set from a user;

controlling a focus of a lens in the camera unit to be set to a first focus level when the control signal set indicates a normal photograph mode;

controlling the focus of the lens in the camera unit to be set to a second focus level different from the first focus level when the control signal set indicates a fingerprint photograph mode;

controlling the camera unit to capture a plurality of fingerprint images when the lens is set to a plurality of the second focus levels; and

generating an enhanced fingerprint image with more uniform focus and brightness than said plurality of fingerprint images using said plurality of fingerprint images.

11. The electronic device of claim 10 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the step of:

controlling the camera unit to capture a user-determined image when the lens is set to the first focus level.

12. The electronic device of claim 10 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the step of:

extracting and storing characteristics information of the enhanced fingerprint image in the memory when the control signal set indicates registration of the user.

13. The electronic device of claim 10 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the step of:

extracting and comparing characteristics information of the enhanced fingerprint image with registered characteristics information from the memory when the control signal set indicates authentication of the user.

14. The electronic device of claim 10 , further comprising:

an illuminating device in the camera unit;

and wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the step of:

controlling the illuminating device to emit light toward a fingerprint location when the control signal set indicates the fingerprint photograph mode.

15. The electronic device of claim 14 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the step of:

controlling the illuminating device to turn off the light toward the fingerprint location when the control signal set indicates the normal photograph mode.

16. The electronic device of claim 10 , wherein the electronic device is a mobile phone.

17. The electronic device of claim 10 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the steps of:

controlling the lens to move to a first focal position when the control signal set indicates the normal photograph mode; and

controlling the lens to move to a second focal position when the control signal set indicates the fingerprint photograph mode.

18. The electronic device of claim 10 , wherein execution of the sequences of instructions by the data processor causes the data processor to further perform the steps of:

controlling a bias on the lens to be a first voltage to set the lens to have a first focal thickness when the control signal set indicates the normal photograph mode; and

controlling the bias on the lens to be a second voltage to set the lens to have a second focal thickness when the control signal set indicates the fingerprint photograph mode.