Fingerprint reading system

A fingerprint reading method, comprising the steps of:

• detecting whether an object is in a scanning region;
• initiating an illumination unit;
• initiating an image capture unit and a liquid lens unit;
• adjusting focus distance of the image capture unit by the liquid lens unit across an entire scanning region from far to near or from near to far and scanning;
• capturing a plurality of subsequent images across the entire scanning region;
• a fingerprint image with the highest quality from the plurality of subsequent images captured by the image capture unit;
• and
• converting the highest quality fingerprint image as a standard fingerprint file;
• wherein in the step of initiating the illumination unit further comprising:
• applying a first lighting with a white light as the illumination unit before initiating the image capture unit and liquid lens unit to focus across the entire scanning region and capturing a plurality of subsequent images;
• applying a second lighting with a monochromic light, such as a red light or near infrared light, as the illumination unit, initiating the image capture unit and liquid lens unit, and converting the highest quality fingerprint image from the plurality of subsequent images captured;
• and
• analyzing an image file captured by the first lighting and a separate image file captured by the second lighting with a signal processing module.