CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of the filing date of Chinese Patent Application No. 201810031167.2 filed on Jan. 12, 2018, the disclosure of which is hereby incorporated in its entirety by reference.

TECHNICAL FIELD

This disclosure relates to a display technology, in particular, to an ultrasonic fingerprint detection circuit, an ultrasonic fingerprint detection method, and a display apparatus.

BACKGROUND

Ultrasonic fingerprint detection technology is an emerging fingerprint identification technology. In the ultrasonic fingerprint detection technology, an ultrasonic fingerprint detection circuit sends a nearly planar ultrasonic wave to a finger. The planar ultrasonic wave interacts with valleys and ridges of the fingerprint, which have different reflectivity. Accordingly, different echo signals are generated. The ultrasonic fingerprint detection circuit can receive and analyze the different echo signals to obtain fingerprint information of the finger being detected.

BRIEF SUMMARY

Accordingly, one example of the present is an ultrasonic fingerprint detection assembly. The ultrasonic fingerprint detection assembly may include an ultrasonic fingerprint detection circuit; and a living body detection circuit. The ultrasonic fingerprint detection circuit may include a plurality of ultrasonic sensors distributed in an array mode, and the plurality of the ultrasonic sensors may include first electrodes and second electrodes opposite the first electrodes respectively. The living body detection circuit may be configured to carry out living body detection at a rest stage of the ultrasonic fingerprint detection circuit.

The ultrasonic fingerprint detection circuit may further include a plurality of first wirings and a plurality of second wirings. The plurality of the first wirings may be coupled to the first electrodes respectively and extends in parallel in a first direction. The plurality of the second wirings may be coupled to the second electrodes respectively and extends in parallel in a second direction. The first direction intersects the second direction.

The living body detection circuit may include a plurality of first touch electrodes extending in parallel in a third direction and a plurality of second touch electrodes extending in parallel in a fourth direction. The third direction intersects the fourth direction. The first direction and the third direction may be the same, and the second direction and the fourth direction may be the same. A plurality of rhombic structures may be disposed at non-overlapping parts of the first touch electrodes and the second touch electrodes. Each of the plurality of the rhombic structures may have a side in a range of approximately 1 mm to approximately 5 mm. A number of the plurality of the first wirings may form the first touch electrodes. A capacitor structure may be formed between the number of the plurality of the first wirings as the first touch electrodes and the second touch electrodes.

The living body detection circuit may include a plurality of touch electrodes and a plurality of touch wirings. The plurality of touch electrodes may be coupled to the plurality of touch wirings respectively. The plurality of first wirings may be divided into a plurality of regions through a timing sequence, and a number of the first wirings in each of the plurality of regions form one of the touch electrodes. A number of the first wirings may form the touch wirings.

The ultrasonic fingerprint detection circuit may be a cMUT array.

Another embodiment of the present disclosure is an ultrasonic fingerprint detection method using the ultrasonic fingerprint detection assembly according to an embodiment of the present disclosure. The ultrasonic fingerprint detection method may include a fingerprint detection stage and a living body detection stage. The living body detection stage may be at a rest stage of the fingerprint detection stage. The ultrasonic fingerprint detection assembly may be configured to determine whether a subject being detected is a living body by detecting a change of capacitance during the living body detection stage.

In one embodiment, the ultrasonic fingerprint detection assembly may be configured to determine whether a subject being detected is a living body by detecting a change of capacitance between the first touch electrodes and the second touch electrodes of the living body detection circuit during the living body detection stage.

In one embodiment, the ultrasonic fingerprint detecting assembly may be configured to determine whether a subject being detected is a living body by detecting a change of capacitance between the touch electrodes of the living body detection circuit and the ground during the living body detection stage.

The electrode wirings at non-overlapping part of the ultrasonic fingerprint detection circuit and the living body detection circuit may be provided with signals which are synchronous with detection signal of the living body detection circuit during the living body detection stage.

Another embodiment of the present disclosure is a display apparatus. The display apparatus may include the ultrasonic fingerprint detection assembly according to one embodiment of the present disclosure.

