TWI691882B - Fingerprint sensing method, fingerprint sensor and information processing device capable of automatically adjusting sensing signal processing parameters - Google Patents

Abstract

A fingerprint sensing method capable of automatically adjusting sensing signal processing parameters includes: setting a plurality of sensing signal processing parameter combinations, which are used to perform an offset and amplification operation on a sensing signal during a signal acquisition operation An analog signal is generated, and the analog signal is used to generate a digital value through an analog-to-digital conversion operation, and is used to perform a reversal operation on the digital value during a signal restoration operation; The sensing signal processing parameter combination generates a maximum value and a minimum value of the plurality of first sensing signal restoration values that can be generated by performing the signal acquisition operation and the signal restoration operation to generate a first range, in the plurality of Select one of the first ranges as a preset sensing value range, and set a combination of the sensing signal processing parameters corresponding to the preset sensing value range as a preset parameter combination; Set a parameter combination to perform a fingerprint collection operation, perform the signal collection operation and the signal restoration operation on the plurality of the sensing signals corresponding to the plurality of fingerprint pixels to generate a plurality of second sensing signal restoration values, and according to The maximum and minimum values of the plurality of restored values of the second sensing signals generate a second range; a final range greater than and closest to the second range is selected from the plurality of the first ranges, and the A sensing signal processing parameter combination corresponding to the final range is set as a final parameter combination; and performing the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data.

Description

Fingerprint sensing method and fingerprint sensor capable of automatically adjusting sensing signal processing parameters And information processing device

The invention relates to an automatic parameter adjustment device and automatic parameter adjustment method, in particular to an automatic parameter adjustment device and method for images.

With the development and progress of science and technology, biometrics (such as fingerprint recognition) has been widely used in various fields, such as fingerprint recognition, mobile phone fingerprint recognition unlocking or identity recognition, etc., which exist in people's daily life in large numbers.

Most existing fingerprint recognition uses a capacitive sensor for recognition. However, due to differences in packaging, voltage, or human body, the capacitive fingerprint sensor makes a large difference in the sensed capacitance. Sometimes it is too large or even beyond the quantization range of the analog-to-digital converter, causing saturation or truncation. Sometimes it is so small that it is concentrated in a small range of values.

In order to make full use of the quantization depth of the analog-to-digital converter, different magnifications or offsets will be set to distribute the collected fingerprint data within a reasonable range. Therefore, in practical applications, it is often traversing multiple parameters and repeatedly acquiring images to find suitable gain and offset parameters, which takes a lot of time.

In order to solve the above-mentioned problems, there is an urgent need in the art for a novel sensing parameter adjustment technique of a fingerprint sensor.

An object of the present invention is to provide a fingerprint sensing method capable of automatically adjusting sensing signal processing parameters, which can perform a fingerprint collection operation by automatically selecting a final parameter combination among a plurality of sensing signal processing parameter combinations, wherein, The range of the sensed value that the final parameter combination can process is just larger than the range of the sensed value of one frame of fingerprint generated by the fingerprint collection operation.

Another object of the present invention is to provide a fingerprint sensor which can automatically select a final parameter combination among a plurality of sensing signal processing parameter combinations to perform a fingerprint collection operation, which In this case, the range of the sensed value that the final parameter combination can process is just larger than the range of the sensed value of one frame of fingerprint generated by the fingerprint collection operation.

Another object of the present invention is to provide an information processing device having a fingerprint sensor, and the fingerprint sensor can automatically select a final parameter combination among a plurality of sensing signal processing parameter combinations to perform a fingerprint collection In the operation, the range of the sensed value that the final parameter combination can process is just larger than the range of the sensed value of one frame of fingerprint generated by the fingerprint collection operation.

In order to achieve the above purpose, a fingerprint sensing method for automatically adjusting sensing signal processing parameters is proposed, which is implemented through a control circuit and includes the following steps: setting a plurality of sensing signal processing parameter combinations, wherein, the sensing The measured signal processing parameter combination includes an offset value and an amplification factor for the control circuit to perform a signal acquisition operation to obtain a digital value. The signal acquisition operation includes performing an offset and amplification operation on a sensing signal To generate an analog signal, and perform an analog-to-digital conversion operation on the analog signal to generate the digital value; and for the control circuit to perform a signal restoration operation, the signal restoration operation includes using the offset value and The magnification factor performs a reversal operation on the digital value; detecting a plurality of first senses that can be generated by performing the signal acquisition operation and the signal restoration operation according to a combination of the plurality of sensing signal processing parameters The maximum and minimum values of the signal restoration value to generate a first range, one of the first ranges is selected as a preset sensing value range, and the corresponding to the preset sensing value range A combination of the sensing signal processing parameters is set as a preset parameter combination; a fingerprint collection operation is performed according to the preset parameter combination, and the signal collection is performed on the plurality of sensing signals corresponding to the plurality of fingerprint pixels Operation and the signal restoration operation to generate a plurality of second sensing signal restoration values, and generating a second range according to the maximum and minimum values of the plurality of second sensing signal restoration values; Selecting a final range larger than and closest to the second range in the first range, and setting a combination of the sensing signal processing parameters corresponding to the final range as a final parameter combination; and proceeding according to the final parameter combination The fingerprint collection operation described above to obtain a frame of digital Pattern information.

In an embodiment, the preset sensing value range is the largest range among the plurality of the first ranges.

In a possible embodiment, the sensing signal may be a capacitive sensing signal, an optical sensing signal, or an acoustic wave sensing signal.

In order to achieve the above object, the present invention further discloses a fingerprint sensor having a sensing array and a control circuit for driving the sensing array. The control circuit is used to execute an automatic adjustment of sensing signal processing parameters The fingerprint sensing method includes the following steps: setting a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include an offset value and an amplification factor for the control circuit to perform a A signal acquisition operation to obtain a digital value. The signal acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and performing an analog-to-digital conversion operation on the analog signal to generate the digital value Value; and for the control circuit to perform a signal recovery operation, the signal recovery operation includes using the offset value and the magnification to perform a reversal operation on the digital value; detection of a plurality of sensing signal processing parameters Combining the maximum value and the minimum value of the plurality of first sensing signal restoration values that can be generated by performing the signal acquisition operation and the signal restoration operation to produce a first range, in which the plurality of first Select one of the ranges to be a preset sensing value range, and set a combination of the sensing signal processing parameters corresponding to the preset sensing value range as a preset parameter combination; proceed according to the preset parameter combination A fingerprint collection operation, performing the signal collection operation and the signal restoration operation on the plurality of sensing signals corresponding to the plurality of fingerprint pixels to generate a plurality of second sensing signal restoration values, and according to the plurality of The maximum value and the minimum value in the restored value of the second sensing signal generate a second range; a final range greater than and closest to the second range is selected from the plurality of first ranges, and will be combined with the final range One of the sensing signal processing parameter combinations corresponding to the range is set as a final parameter combination; and Perform the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data.

In an embodiment, the preset sensing value range is the largest range among the plurality of the first ranges.

In a possible embodiment, the sensing array may be a capacitive sensing array, an optical sensing array, or an acoustic wave sensing array.

In addition, the present invention further discloses an information processing device having a central processing unit and the fingerprint sensor as described above, wherein the central processing unit is coupled to the capacitive fingerprint sensor to receive the Digital fingerprint data.

In a possible embodiment, the information processing device may be a smart phone or a portable computer device.

In order to enable your reviewer to further understand the structure, features and purpose of the present invention, the drawings and detailed description of the preferred embodiments are attached as follows.

100: fingerprint sensor

110: sensing array

120: control circuit

200: Information processing device

210: CPU

220: Fingerprint sensor

Step a: Set a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include an offset value and an amplification factor, which are used for the control circuit to perform a signal acquisition operation to obtain a digital value The signal acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and performing an analog-to-digital conversion operation on the analog signal to generate the digital value; and for the control The circuit performs a signal restoration operation which includes performing a reverse operation on the digital value

Step b: Detecting the maximum value and minimum value of the plurality of first sensing signal restoration values that can be generated by performing the signal acquisition operation and the signal restoration operation according to the combination of the plurality of sensing signal processing parameters to generate a The first range, one of the first ranges is selected as a preset sensing value range, and a combination of the sensing signal processing parameters corresponding to the preset sensing value range is set as a pre-set Set parameter combinations

Step c: Perform a fingerprint collection operation according to the preset parameter combination, perform the signal collection operation and the signal restoration operation on the plurality of sensing signals corresponding to the plurality of fingerprint pixels to generate a plurality of second sensing signal restorations Value, and a second range is generated according to the maximum and minimum values of the restored values of the second sensing signals

Step d: Select a final range greater than and closest to the second range from among the plurality of first ranges, and set a combination of the sensing signal processing parameters corresponding to the final range as a final parameter combination

Step e: Perform the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data

FIG. 1 illustrates a flowchart of an embodiment of a fingerprint sensing method for automatically adjusting sensing signal processing parameters of the present invention.

FIG. 2 is a block diagram of an embodiment of the fingerprint sensor of the present invention.

3 is a block diagram of an embodiment of the information processing device of the present invention.

Please refer to FIG. 1, which illustrates a flow chart of an embodiment of a fingerprint sensing method for automatically adjusting sensing signal processing parameters of the present invention, wherein the fingerprint sensing method is implemented by a control circuit.

As shown in FIG. 1, the fingerprint sensing method for automatically adjusting sensing signal processing parameters includes the following steps: setting a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include an offset value and a The amplification factor is used for the control circuit to perform a signal acquisition operation to obtain a digital value. The signal acquisition operation includes performing an offset and amplification operation on a sensing signal to produce Generating an analog signal, and performing an analog-to-digital conversion operation on the analog signal to generate the digital value; and for the control circuit to perform a signal restoration operation, the signal restoration operation includes using the offset value and the The magnification factor performs a reverse operation on the digital value (step a); detecting a plurality of combinations of the sensing signal processing parameters to perform the signal acquisition operation and the signal restoration operation can generate a plurality of firsts The maximum value and the minimum value in the restored value of the sensing signal to generate a first range, one of the plurality of the first ranges is selected as a preset sensing value range, and will be combined with the preset sensing value range A corresponding one of the sensing signal processing parameter combinations is set as a preset parameter combination (step b); a fingerprint collection operation is performed according to the preset parameter combination, and the plurality of sensing signals corresponding to the plurality of fingerprint pixels Performing the signal acquisition operation and the signal restoration operation to generate a plurality of second sensing signal restoration values, and generating a second according to the maximum value and the minimum value of the plurality of second sensing signal restoration values Range (step c); select a final range greater than and closest to the second range from the plurality of first ranges, and set a combination of the sensing signal processing parameters corresponding to the final range as a final Parameter combination (step d); and performing the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data (step e).

In step a, the analog-to-digital conversion operation is implemented using an analog-to-digital conversion (ADC). Taking an 8-bit analog-to-digital converter as an example, the digital value range after the analog-to-digital conversion operation is 0~255, and the digital value range (0~255) is composed of different sensing signal processing parameters ( Including the offset value and magnification), it corresponds to different sensing signal values. Therefore, the reversal operation is to use the sensor signal processing parameter combination (including the offset value and magnification) to The digital value performs the inverse operation of the offset and amplification operation (that is, performs a division operation and an offset restoration operation) to obtain the corresponding sensing signal value. Although in the above description, the sensing signal processing parameter combination takes the offset value and the magnification as an example, the present invention is not limited to this, and it may also include other parameters used in the field of signal processing .

In addition, the preset sensing value range may be the largest range among the plurality of the first ranges.

In addition, the sensing signal may be a capacitive sensing signal, an optical sensing signal or an acoustic wave sensing signal.

That is to say, by automatically selecting the final parameter combination among the plurality of sensing signal processing parameter combinations to perform a fingerprint collection operation, the present invention can adaptively select the sensing parameters to avoid saturation of the sensing signal or The truncation phenomenon, so as to correctly obtain a frame of digital fingerprint data.

According to the above description, the present invention further provides a fingerprint sensor. Please refer to FIG. 2, which illustrates a block diagram of an embodiment of the fingerprint sensor of the present invention. As shown in FIG. 2, a fingerprint sensor 100 has a sensing array 110 and a control circuit 120 for driving the sensing array 110, wherein the sensing array 110 may be a capacitive sensing array, an optical Sensing array or an acoustic wave sensing array, and the control circuit 120 is used to execute a fingerprint sensing method that can automatically adjust sensing signal processing parameters, which includes the following steps: (1) setting a plurality of sensing signal processing Parameter combination, wherein the sensing signal processing parameter combination includes an offset value and an amplification factor for the control circuit 120 to perform a signal acquisition operation on the sensing array 110 to obtain a digital value, the signal The acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and performing an analog-to-digital conversion operation on the analog signal to generate the digital value; and for the control circuit 120 to perform A signal restoration operation, which includes performing a reversal operation on the digital value, wherein the reversal operation is performed on the digital value using the sensing signal processing parameter combination (including the offset value and the magnification) Inverse operation of the offset and amplification operation (that is, division operation and offset restoration operation); (2) Detection of the signal acquisition operation and the signal restoration operation according to a plurality of combinations of the sensing signal processing parameters The maximum and minimum values of the plurality of first sensing signal restoration values that can be generated to generate a first range, one of the plurality of first ranges is used as a preset sensing value range, and the A combination of the sensing signal processing parameters corresponding to the preset sensing value range is set as a preset parameter combination; (3) performing a fingerprint collection operation on the sensing array 110 according to the preset parameter combination A plurality of the sensing signals corresponding to the fingerprint pixels perform the signal acquisition operation and the signal restoration operation to generate a plurality of second sensing signal restoration values, and the largest of the plurality of second sensing signal restoration values The value and the minimum value produce a second range; (4) select from a plurality of the first ranges greater than and closest to the second range The final range, and setting a sensing signal processing parameter combination corresponding to the final range as a final parameter combination; and (5) performing the fingerprint collection operation on the sensing array 110 according to the final parameter combination to Obtain a frame of digital fingerprint data.

That is to say, through the control circuit 120 automatically selecting the final parameter combination among the plurality of sensing signal processing parameter combinations for a fingerprint collection operation, the fingerprint sensor 100 can adaptively select the sensing parameter to avoid The sensing signal is saturated or truncated, so that a frame of digital fingerprint data is correctly obtained from the sensing array 110.

According to the above description, the present invention further provides an information processing device. Please refer to FIG. 3, which illustrates a block diagram of an embodiment of the information processing device of the present invention. As shown in FIG. 3, an information processing device 200 includes a central processing unit 210 and a fingerprint sensor 220, wherein the fingerprint sensor 220 is composed of the fingerprint sensor 100 shown in FIG. 2, and the central processing unit The 210 is coupled to the fingerprint sensor 220 to receive the digital fingerprint data.

With the design disclosed above, the present invention has the following advantages:

1. The fingerprint sensing method of the present invention can automatically select a final parameter combination among a plurality of sensing signal processing parameter combinations to perform a fingerprint acquisition operation to avoid saturation or truncation of the sensing signal, thereby correctly obtaining a frame Digital fingerprint data.

2. The fingerprint sensing method of the present invention can simplify the adjustment process of sensing signal processing parameter combinations.

3. The fingerprint sensing method of the present invention can reduce the calibration cost of the fingerprint sensor.

The case disclosed in this case is a preferred embodiment, and any part of the modification or modification that originates from the technical idea of this case and can be easily inferred by those skilled in the art, does not deviate from the patent scope of this case.

In summary, regardless of the purpose, means and efficacy of this case, it shows that it is very different from the conventional technology, and its first invention is practical and practical, and it does meet the patent requirements of the invention. I urge your review committee to investigate and give the patent as soon as possible. Society is for supreme prayer.

Step a: Set a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include an offset value and an amplification factor, which are used for the control circuit to perform a signal acquisition operation to obtain a digital value The signal acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and performing an analog-to-digital conversion operation on the analog signal to generate the digital Value; and for the control circuit to perform a signal recovery operation, the signal recovery operation includes using the offset value and the amplification factor to perform a reverse operation on the digital value

Step b: Detecting the maximum and minimum values of the plurality of first sensing signal restoration values that can be generated by performing the signal acquisition operation and the signal restoration operation according to the plurality of sensing signal processing parameter combinations Generating a first range, selecting one of the plurality of the first ranges as a preset sensing value range, and setting a combination of the sensing signal processing parameters corresponding to the preset sensing value range as A preset parameter combination

Step c: Perform a fingerprint collection operation according to the preset parameter combination, and perform the signal collection operation and the signal restoration operation on the plurality of sensing signals corresponding to the plurality of fingerprint pixels to generate a plurality of second sensing Signal restoration value, and generating a second range according to the maximum value and minimum value of the plurality of second sensing signal restoration values

Step d: Select a final range greater than and closest to the second range from among the plurality of first ranges, and set a combination of the sensing signal processing parameters corresponding to the final range as a final parameter combination

Step e: Perform the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data

Claims (8)

A fingerprint sensing method capable of automatically adjusting sensing signal processing parameters is implemented by a control circuit and includes the following steps: setting a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include a The offset value and an amplification factor are used for the control circuit to perform a signal acquisition operation to obtain a digital value. The signal acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and Performing an analog-to-digital conversion operation on the analog signal to generate the digital value; and for the control circuit to perform a signal restoration operation, the signal restoration operation including using the offset value and the amplification factor to the digital value Perform a reversal operation; detect the maximum value among the plurality of restored values of the first sensed signal that can be generated by performing the signal acquisition operation and the signal restoration operation according to the combination of the plurality of sensed signal processing parameters And the minimum value to generate a first range, one of the first ranges is selected as a preset sensing value range, and a sensing signal corresponding to the preset sensing value range is processed The parameter combination is set as a preset parameter combination; a fingerprint acquisition operation is performed according to the preset parameter combination, and the signal acquisition operation and the signal restoration are performed on the plurality of sensing signals corresponding to the plurality of fingerprint pixels Operating to generate a plurality of restored values of the second sensing signal, and generating a second range according to the maximum value and the minimum value of the plurality of restored values of the second sensing signal; selecting from the plurality of the first ranges greater than And a final range closest to the second range, and setting a sensing signal processing parameter combination corresponding to the final range as a final parameter combination; and performing the fingerprint collection operation according to the final parameter combination to Obtain a frame of digital fingerprint data. The fingerprint sensing method capable of automatically adjusting sensing signal processing parameters according to claim 1, wherein the preset sensing value range is the largest range among the plurality of the first ranges. The fingerprint sensing method capable of automatically adjusting sensing signal processing parameters according to claim 1, wherein the sensing signal is a capacitive sensing signal, an optical sensing signal, or an sonic sensing signal. A fingerprint sensor has a sensing array and a control circuit for driving the sensing array. The control circuit is used to execute a fingerprint sensing method that can automatically adjust sensing signal processing parameters, which includes the following Step: Set a plurality of sensing signal processing parameter combinations, wherein the sensing signal processing parameter combinations include an offset value and an amplification factor, which are used for the control circuit to perform a signal acquisition operation on the sensing array, Obtaining a digital value, the signal acquisition operation includes performing an offset and amplification operation on a sensing signal to generate an analog signal, and performing an analog digital conversion operation on the analog signal to generate the digital value; and using For the control circuit to perform a signal restoration operation, the signal restoration operation includes performing a reversal operation on the digital value by using the offset value and the amplification factor; the detection is performed according to a plurality of combinations of the sensing signal processing parameters The maximum and minimum values of the plurality of first sensing signal restoration values that can be generated by the signal acquisition operation and the signal restoration operation to generate a first range, and select one of the plurality of first ranges Used as a preset sensing value range, and setting a combination of the sensing signal processing parameters corresponding to the preset sensing value range as a preset parameter combination; according to the preset parameter combination, the sensing array Performing a fingerprint collection operation, performing the signal collection operation and the signal restoration operation on the plurality of sensing signals corresponding to the plurality of fingerprint pixels to generate a plurality of second sensing signal restoration values, and according to the complex number The maximum and minimum values of the restored values of the second sensing signals generate a second range; a final range greater than and closest to the second range is selected from the plurality of first ranges, and A sensing signal processing parameter combination corresponding to the final range is set as a final parameter combination; and performing the fingerprint collection operation according to the final parameter combination to obtain a frame of digital fingerprint data. The fingerprint sensor according to claim 4, wherein the preset sensing value range is the largest range among the plurality of the first ranges. The fingerprint sensor according to claim 4, wherein the sensing array is a capacitive sensing array, an optical sensing array, or an acoustic wave sensing array. An information processing device having a central processor and any one of items 4-6 The fingerprint sensor according to item 1, wherein the central processing unit is coupled to the fingerprint sensor to receive the digital fingerprint data. The information processing device according to claim 7, which is a smart phone or a portable computer device.

Images