Fingerprint detection device and mobile terminal
Disclosed are a fingerprint detection device and a mobile terminal. The fingerprint detection apparatus comprises a capacitive fingerprint sensor and a capacitive touch control chip which is electrically connected to the capacitive fingerprint sensor; wherein the capacitive fingerprint sensor is configured to collect fingerprint information and convert the fingerprint information to an analog signal; and the capacitive touch control chip is configured to convert the analog signal to a digital signal, and generate fingerprint image information according to the digital signal. As compared with the dedicated control chip in the related art, the capacitive touch control chip has mature design and manufacture technique, and thus the manufacture and application costs are lower.
1. A fingerprint detection apparatus, comprising:
a capacitive fingerprint sensor configured to collect fingerprint information and convert the fingerprint information to an analog signal; and
a capacitive touch control chip which is electrically connected to the capacitive fingerprint sensor and configured to convert the analog signal to a digital signal, and generate fingerprint image information according to the digital signal, wherein the capacitive fingerprint sensor comprises a fingerprint scanning analog front end, the capacitive touch control chip comprises a first analog front end and a first digital logic circuit, and the fingerprint scanning analog front end is respectively electrically connected to the first analog front end and the first digital logic circuit.
2. The fingerprint detection apparatus according to claim 1 , wherein:
the capacitive fingerprint sensor comprises an annular emitter electrode; and
wherein the annular emitter electrode is electrically connected to the first analog front end.
3. The fingerprint detection apparatus according to claim 2 , wherein the first analog front end comprises a driving channel, the driving channel being electrically connected to the annular emitter electrode.
4. The fingerprint detection apparatus according to claim 3 , wherein:
the first analog front end comprises a sensing input channel; and
the fingerprint scanning analog front end comprises a second digital logic circuit and an analog signal snubber circuit;
wherein the second digital logic circuit is electrically connected to the first digital logic circuit, and the analog signal snubber circuit is electrically connected to the sensing input channel.
5. The fingerprint detection apparatus according to claim 4 , wherein the fingerprint scanning analog front end further comprises a row and column analog switch, the row and column analog switch being configured to switch, in a time sharing manner, a scanning region of data scanning performed by the capacitive touch control chip to the capacitive fingerprint sensor.
6. The fingerprint detection apparatus according to claim 3 , wherein the capacitive touch control chip comprises an analog-to-digital conversion unit, a processing unit and a fingerprint identification unit; wherein the analog-to-digital conversion unit is configured to convert the analog signal to a digital signal, the processing unit is configured to generate fingerprint image information according to the digital signal, and the fingerprint identification unit is configured to perform fingerprint identification according to the fingerprint image information.
7. The fingerprint detection apparatus according to claim 3 , wherein the capacitive fingerprint sensor is provided with a plurality of induction electrodes; the plurality of induction electrodes forming an induction electrode matrix; and the induction electrode matrix being circumferentially provided with a compensation electrode.
8. The fingerprint detection apparatus according to claim 7 , wherein:
a plurality of compensation electrodes is provided and arranged around the induction electrode matrix; or
the compensation electrode is an annular compensation electrode and is arranged surrounding the induction electrode matrix.
9. The fingerprint detection apparatus according to claim 3 ,
wherein the capacitive fingerprint sensor is provided with an induction electrode matrix which is formed by a plurality of induction electrodes;
wherein the capacitive fingerprint sensor reuses the capacitive touch control chip in a time sharing manner such that the capacitive touch control chip performs regional scanning for the sensor electrode matrix in a time sharing manner; and
wherein the capacitive touch control chip scans at least three induction electrodes each time and reads only data of an induction electrode located at the center of the scanning region.
10. The fingerprint detection apparatus according to claim 2 , wherein:
the first analog front end comprises a sensing input channel; and
the fingerprint scanning analog front end comprises a second digital logic circuit and an analog signal snubber circuit;
wherein the second digital logic circuit is electrically connected to the first digital logic circuit, and the analog signal snubber circuit is electrically connected to the sensing input channel.
11. The fingerprint detection apparatus according to claim 2 , wherein the capacitive touch control chip comprises an analog-to-digital conversion unit, a processing unit and a fingerprint identification unit; wherein the analog-to-digital conversion unit is configured to convert the analog signal to a digital signal, the processing unit is configured to generate fingerprint image information according to the digital signal, and the fingerprint identification unit is configured to perform fingerprint identification according to the fingerprint image information.
12. The fingerprint detection apparatus according to claim 2 , wherein the capacitive fingerprint sensor is provided with a plurality of induction electrodes; the plurality of induction electrodes forming an induction electrode matrix; and the induction electrode matrix being circumferentially provided with a compensation electrode.
13. The fingerprint detection apparatus according to claim 2 ,
wherein the capacitive fingerprint sensor is provided with an induction electrode matrix which is formed by a plurality of induction electrodes;
wherein the capacitive fingerprint sensor reuses the capacitive touch control chip in a time sharing manner such that the capacitive touch control chip performs regional scanning for the sensor electrode matrix in a time sharing manner; and
wherein the capacitive touch control chip scans at least three induction electrodes each time and reads only data of an induction electrode located at the center of the scanning region.
14. The fingerprint detection apparatus according to claim 1 , wherein the capacitive touch control chip comprises an analog-to-digital conversion unit, a processing unit and a fingerprint identification unit; wherein the analog-to-digital conversion unit is configured to convert the analog signal to a digital signal, the processing unit is configured to generate fingerprint image information according to the digital signal, and the fingerprint identification unit is configured to perform fingerprint identification according to the fingerprint image information.
15. The fingerprint detection apparatus according to claim 1 , wherein the capacitive fingerprint sensor is provided with a plurality of induction electrodes; the plurality of induction electrodes forming an induction electrode matrix; and the induction electrode matrix being circumferentially provided with a compensation electrode.
16. The fingerprint detection apparatus according to claim 1 ,
wherein the capacitive fingerprint sensor is provided with an induction electrode matrix which is formed by a plurality of induction electrodes;
wherein the capacitive fingerprint sensor reuses the capacitive touch control chip in a time sharing manner such that the capacitive touch control chip performs regional scanning for the sensor electrode matrix in a time sharing manner; and
wherein the capacitive touch control chip scans at least three induction electrodes each time and reads only data of an induction electrode located at the center of the scanning region.
17. The fingerprint detection apparatus according to claim 1 , wherein the capacitive fingerprint sensor comprises an annular emitter electrode, and the capacitive touch control chip is configured to:
judge whether the annular emitter electrode is touched;
control the capacitive fingerprint sensor to enter a power saving mode, if the annular emitter electrode is not touched; and
control the capacitive fingerprint sensor to enter an operating mode, if the annular emitter electrode is touched.
18. The fingerprint detection apparatus according to claim 17 , wherein the capacitive touch control chip is configured to:
detect whether a parasitic capacitance of the annular emitter electrode is a predetermined value;
judge that the annular emitter electrode is not touched, if the parasitic capacitance is the predetermined value; and
judge that the annular emitter electrode is touched, if the parasitic capacitance is not the predetermined value.
19. A mobile terminal, comprising:
a fingerprint detection apparatus, wherein the fingerprint detection apparatus comprises:
a capacitive fingerprint sensor configured to collect fingerprint information and convert the fingerprint information to an analog signal; and
a capacitive touch control chip which is electrically connected to the capacitive fingerprint sensor, and configured to convert the analog signal to a digital signal and generate fingerprint image information according to the digital signal,
wherein the capacitive fingerprint sensor comprises a fingerprint scanning analog front end, the capacitive touch control chip comprises a first analog front end and a first digital logic circuit, and the fingerprint scanning analog front end is respectively electrically connected to the first analog front end and the first digital logic circuit.
20. The mobile terminal according to claim 19 , wherein the capacitive fingerprint sensor is provided with a plurality of induction electrodes; the plurality of induction electrodes forming an induction electrode matrix; and the induction electrode matrix being circumferentially provided with a compensation electrode.