CN-121999517-A - Fingerprint sensing chip, fingerprint module and signal processing method

CN121999517ACN 121999517 ACN121999517 ACN 121999517ACN-121999517-A

Abstract

The application relates to the technical field of fingerprint acquisition and discloses a fingerprint sensing chip, a fingerprint module and a signal processing method. The fingerprint sensing chip comprises a fingerprint acquisition module, a first interface module, a processing module and a processing module, wherein the fingerprint acquisition module is used for acquiring fingerprint signals, the first interface module is used for reading pressure signals acquired by a pressure sensor through the first interface module, the processing module is used for processing the fingerprint signals to obtain first electric signals representing fingerprint information, and the processing module is used for processing the pressure signals to obtain second electric signals representing pressure. The fingerprint sensing chip provided by the application has strong function expansibility, can directly read the pressure signal acquired by the pressure sensor, saves the hardware cost of a driving circuit of the peripheral pressure sensor, and improves the signal transmission quality.

Inventors

YANG JINLIANG
WANG HAISHENG
LIU XIAOLONG
WANG PENGPENG

Assignees

天津极豪科技有限公司

Dates

Publication Date: 20260508
Application Date: 20250819

Claims (12)

1. A fingerprint sensing chip, comprising: the fingerprint acquisition module is used for acquiring fingerprint signals; The fingerprint sensing chip reads pressure signals acquired by the pressure sensor through the first interface module; The processing module is used for processing the fingerprint signals to obtain first electric signals representing fingerprint information, and processing the pressure signals to obtain second electric signals representing pressure.
2. The fingerprint sensing chip according to claim 1, wherein said first interface module comprises a first PAD and/or a second PAD; The first end of the first PAD is connected with a pressure sensor, and the fingerprint sensing chip reads pressure signals acquired by the pressure sensor through the first PAD; The fingerprint sensing chip supplies power to the pressure sensor through the second PAD.
3. The fingerprint sensing chip of claim 2, wherein the first interface module further comprises a pull-down resistor with an adjustable resistance, the pull-down resistor being connected between a ground terminal and a second terminal of the first PAD.
4. The fingerprint sensing chip of claim 1, the fingerprint sensing chip is characterized by further comprising: the first filtering module is used for filtering the pressure signal to obtain a filtered pressure signal; The processing module is used for processing the filtered pressure signal to obtain a second electric signal representing the pressure.
5. The fingerprint sensing chip according to claim 1, wherein said processing module comprises at least a first analog-to-digital conversion unit and a second analog-to-digital conversion unit; The first analog-to-digital conversion unit is used for performing analog-to-digital conversion on the fingerprint signals acquired by the fingerprint acquisition module to obtain first electric signals representing fingerprint information; The second analog-to-digital conversion unit is used for performing analog-to-digital conversion on the pressure signal read by the first interface module to obtain the second electric signal representing the pressure.
6. The fingerprint sensing chip of claim 5, wherein the first and second analog-to-digital conversion units are the same analog-to-digital conversion unit in common, and the processing module further comprises a signal switching unit; The signal switching unit is used for transmitting the fingerprint signals acquired by the fingerprint acquisition module to the same common analog-to-digital conversion unit, or transmitting the pressure signals read by the first interface module to the same common analog-to-digital conversion unit.
7. The fingerprint sensing chip according to any one of claims 1-6, wherein said processing module comprises at least a logic control unit for at least one of: Generating a first interrupt signal according to the second electric signal representing the pressure so as to trigger a processor outside the fingerprint sensing chip to generate a control instruction based on the first interrupt signal; generating a second interrupt signal according to the first electric signal representing fingerprint information and/or the second electric signal representing pressure, receiving an image acquisition instruction generated by the processor based on the second interrupt signal, and triggering the fingerprint acquisition module to acquire fingerprint signals.
8. The fingerprint sensing chip according to any one of claims 1-6, further comprising a second interface module connected between the processing module and a processor external to the fingerprint sensing chip; The processing module sends the first electric signal representing fingerprint information and/or the second electric signal representing pressure to the processor through the second interface module.
9. A fingerprint module, comprising: A pressure sensor; The fingerprint sensing chip according to any one of claims 1-8.
10. The signal processing method applied to the fingerprint module set as claimed in claim 9, comprising: Reading a pressure signal acquired by a pressure sensor through a fingerprint sensing chip in the fingerprint module; And processing the pressure signal through the fingerprint sensing chip to obtain a second electric signal representing the pressure, and generating a first interrupt signal according to the second electric signal representing the pressure so as to trigger a processor outside the fingerprint sensing chip to generate a control instruction based on the first interrupt signal.
11. The signal processing method according to claim 10, further comprising: collecting a first fingerprint signal through the fingerprint sensing chip, wherein the first fingerprint signal is used for determining whether a finger is touched by mistake; determining a signal quantity of the first fingerprint signal through the fingerprint sensing chip; Generating false touch prompt information under the condition that the fingerprint sensing chip determines that the second electric signal representing the pressure is not greater than a pressure signal quantity threshold value or that the signal quantity of the first fingerprint signal is not greater than a fingerprint signal quantity threshold value; Transmitting a second interrupt signal to the processor if the fingerprint sensing chip determines that the second electrical signal representative of pressure is greater than the pressure semaphore threshold and/or if the semaphore of the first fingerprint signal is greater than the fingerprint semaphore threshold; Receiving an image acquisition instruction generated by the processor based on the second interrupt signal; and acquiring a second fingerprint signal according to the image acquisition instruction, wherein the second fingerprint signal is used for fingerprint identification.
12. The method of claim 10, wherein the fingerprint acquisition module in the fingerprint sensing chip comprises a sensing array, the method further comprising: Collecting fingerprint signals line by line through the sensing array, reading pressure signals collected by the pressure sensor once every time at least one line of fingerprint signals are collected in the process of collecting the fingerprint signals line by line, or And after the fingerprint signals of the sensing array are acquired, reading the pressure signals acquired by the pressure sensor for the first time.

Description

Fingerprint sensing chip, fingerprint module and signal processing method Technical Field The present application relates to the field of fingerprint acquisition technologies, and in particular, to a fingerprint sensing chip, a fingerprint module, and a signal processing method. Background The current electronic devices (such as smart phones and tablet personal computers) are usually assembled by splicing a pressure sensor and a fingerprint chip through an FPC (Flexible Printed Circuit Board, flexible circuit board), and pressure data output by the pressure sensor and fingerprint data output by the fingerprint chip are respectively connected to a main control CPU (Central Processing Unit ) of the electronic device. However, the pressure sensor and the fingerprint chip are spliced and assembled in a manner, so that the problems of high complexity and high cost of hardware circuit design exist. And the pressure sensor transmits pressure signals to the main control CPU through an external FPC circuit, so that the quality of data transmission is easily affected by noise interference, and even erroneous fingerprint judgment can be caused. Disclosure of Invention In view of this, the present application aims to provide a fingerprint sensing chip, a fingerprint module and a signal processing method, so as to enhance the function expansibility of the fingerprint chip, simplify the hardware complexity, save the hardware cost and improve the signal transmission quality. In order to achieve the above purpose, the technical scheme of the application is as follows: A first aspect of an embodiment of the present application provides a fingerprint sensing chip, including: the fingerprint acquisition module is used for acquiring fingerprint signals; The fingerprint sensing chip reads pressure signals acquired by the pressure sensor through the first interface module; The processing module is used for processing the fingerprint signals to obtain first electric signals representing fingerprint information, and processing the pressure signals to obtain second electric signals representing pressure. Optionally, the first interface module comprises a first PAD and/or a second PAD; The first end of the first PAD is connected with a pressure sensor, and the fingerprint sensing chip reads pressure signals acquired by the pressure sensor through the first PAD; The fingerprint sensing chip supplies power to the pressure sensor through the second PAD. Optionally, the first interface module further comprises a pull-down resistor with an adjustable resistance value, and the pull-down resistor is connected between a grounding end and a second end of the first PAD. Optionally, the fingerprint sensing chip further comprises: the first filtering module is used for filtering the pressure signal to obtain a filtered pressure signal; The processing module is used for processing the filtered pressure signal to obtain a second electric signal representing the pressure. Optionally, the processing module at least comprises a first analog-to-digital conversion unit and a second analog-to-digital conversion unit; The first analog-to-digital conversion unit is used for performing analog-to-digital conversion on the fingerprint signals acquired by the fingerprint acquisition module to obtain first electric signals representing fingerprint information; The second analog-to-digital conversion unit is used for performing analog-to-digital conversion on the pressure signal read by the first interface module to obtain the second electric signal representing the pressure. Optionally, the first analog-to-digital conversion unit and the second analog-to-digital conversion unit are the same analog-to-digital conversion unit in common, and the processing module further comprises a signal switching unit; The signal switching unit is used for transmitting the fingerprint signals acquired by the fingerprint acquisition module to the same common analog-to-digital conversion unit, or transmitting the pressure signals read by the first interface module to the same common analog-to-digital conversion unit. Optionally, the processing module at least comprises a logic control unit, wherein the logic control unit is used for at least one of the following: Generating a first interrupt signal according to the second electric signal representing the pressure so as to trigger a processor outside the fingerprint sensing chip to generate a control instruction based on the first interrupt signal; generating a second interrupt signal according to the first electric signal representing fingerprint information and/or the second electric signal representing pressure, receiving an image acquisition instruction generated by the processor based on the second interrupt signal, and triggering the fingerprint acquisition module to acquire fingerprint signals. Optionally, the fingerprint sensing chip further comprises a second interface module, wherein the second interface module is conn