Method and apparatus for adjusting excitation voltage of fingerprint detection chip

An apparatus for adjusting an excitation voltage of a fingerprint detection chip, comprising:

• a fingerprint detection chip, wherein the fingerprint detection chip comprises a first detection area, and a second detection area, each of the first detection area and the second detection area has a plurality of detection units, and the first detection area is configured to detect a fingerprint capacitance;
• a metal ring located on the fingerprint detection chip, wherein the metal ring at least partially covers the second detection area;
• a signal transmitting unit, configured to transmit an excitation signal to the metal ring, so as to detect a capacitance value of a coupling capacitance formed between the plurality of detection units in the second detection area and the metal ring;
• or configured to apply the excitation signal to the plurality of detection units in the second detection area when the metal ring is grounded, so as to detect a capacitance value of a coupling capacitance formed between the plurality of detection units in the second detection area and the metal ring;
• and
• a control module, configured to adjust the excitation voltage of the excitation signal of the first detection area according to the capacitance value of the coupling capacitance formed between the plurality of detection units in the second detection area and the metal ring.

A fingerprint detection chip, comprising a signal transmitting unit, a first detection area and a second detection area, wherein:

• each of the first detection area and the second detection area has a plurality of detection units,
• the first detection area is configured to detect a fingerprint capacitance;
• the signal transmitting unit is configured to transmit an excitation signal to a metal ring, so as to detect a capacitance value of a coupling capacitance formed between the plurality of detection units in the second detection area and the metal ring;
• or configured to apply the excitation signal to the plurality of detection units in the second detection area when the metal ring is grounded, so as to detect a capacitance value of a coupling capacitance formed between the plurality of detection units in the second detection area and the metal ring;
• the metal ring is located on the fingerprint detection chip and at least partially covers the second detection area.