TWI765704B - Wake-up method for capacitive fingerprint sensing device, capacitive fingerprint sensing device, touch display panel and information processing device - Google Patents

Abstract

A wake-up method for a capacitive fingerprint sensing device, comprising: generating a first wake-up signal according to a sensing result of at least one capacitive sensing circuit located at at least one periphery of a capacitive sensor array; when the first wake-up signal presents an active state, and when the first wake-up signal is in an inactive state for more than a predetermined period, driving a local area of the capacitive sensor array to perform a touch detection operation to generate a second wake-up signal; and When the second wake-up signal is in an active state, the capacitive sensor array enters a working mode to perform a fingerprint scanning operation.

Description

Wake-up method for capacitive fingerprint sensing device, capacitive fingerprint sensing device, touch display panel and information processing device

The present invention relates to fingerprint verification, in particular to a wake-up solution for a capacitive fingerprint sensing device with a power saving function.

With the popularization and vigorous development of mobile devices, touch display panels have become an indispensable component, and fingerprint verification has also become an essential function.

In general mobile devices, a capacitive fingerprint unlocking key is set at the bottom of the screen to facilitate the user to perform fingerprint unlocking operations. Since the capacitive fingerprint unlocking key performs fingerprint scanning only during the period requiring fingerprint verification, such as during power-on or online financial transactions, the general capacitive fingerprint unlocking key will be dormant during other periods to save power consumption.

In addition, in order for the capacitive fingerprint unlocking key to start a fingerprint verification process, a touch sensing mechanism must be set inside to start the fingerprint verification process when a finger pressing operation is detected. A common method is to determine whether there is a finger pressing operation by detecting a plurality of sensing electrodes in a central area of the capacitive fingerprint unlocking key, and if so, enter a fingerprint scanning procedure.

However, since the detection circuit matched with each sensing electrode in a capacitive fingerprint unlocking key is generally composed of a charge-to-voltage circuit and an analog-to-digital circuit, and the analog-to-digital circuit consumes considerable power, the existing The energy-saving performance of the capacitive fingerprint unlock key still leaves room for improvement.

To solve the above problems, a novel capacitive fingerprint sensing device is urgently needed in the art.

One objective of the present invention is to disclose a wake-up method for a capacitive fingerprint sensing device, which can provide a first-stage wake-up function with low power consumption by arranging capacitive sensing circuits around a fingerprint sensing area.

Another object of the present invention is to disclose a wake-up method for a capacitive fingerprint sensing device, which can detect a touch event in the capacitive sensing circuit, and the capacitive sensing circuit does not detect any touch event for more than a period of time In both cases of the predetermined period, a second-stage wake-up function is provided by detecting a plurality of sensing electrodes in a central area of the fingerprint sensing area, so as to save power consumption and avoid misjudgment. Fingerprint scanner.

To achieve the aforementioned purpose, a wake-up method for a capacitive fingerprint sensing device is proposed, which includes:

generating a first wake-up signal according to a sensing result of at least one capacitive sensing circuit located at at least one periphery of a capacitive sensor array;

When the first wake-up signal is in an active state, and when the first wake-up signal is in an inactive state for more than a predetermined period, a local area of the capacitive sensor array is driven to perform a touch detection operation to generate a touch detection operation. a second wake-up signal; and

When the second wake-up signal is in an active state, the capacitive sensor array is brought into a working mode to perform a fingerprint scanning operation.

In order to achieve the aforementioned purpose, the present invention further provides a capacitive fingerprint sensing device, which has:

a capacitive sensor array located in a fingerprint sensing area, performing a fingerprint scanning operation on the fingerprint sensing area in an active mode, stopping the fingerprint scanning operation in a first phase of a sleep mode, and performing a touch detection operation on a partial area of the fingerprint sensing area in a second stage of the sleep mode to generate a second wake-up signal;

At least one capacitance sensing circuit is distributed in at least one periphery of the fingerprint sensing area, each of the capacitance sensing circuits has a charge-to-voltage circuit and a comparator, wherein, in the first stage, the charge-to-voltage circuit is generating a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a first wake-up signal; and

a control unit for driving the capacitive sensor array to perform the touch when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period A detection operation is performed to generate the second wake-up signal, and when the second wake-up signal exhibits an active state, the capacitive sensor array enters the working mode.

In one embodiment, the capacitive sensor array has a plurality of fingerprint detection circuits, each of the fingerprint detection circuits has a charge-to-voltage circuit to generate an output voltage according to a partial fingerprint, and an analog The digital converter generates a digital output value according to the output voltage.

In one embodiment, the fingerprint sensing area is a square area.

In one embodiment, the capacitive fingerprint sensing device has a substrate for carrying the capacitive sensor array, the at least one capacitive sensing circuit and the control unit.

In one embodiment, the number of the fingerprint detection circuits is greater than the number of the capacitance sensing circuits.

In order to achieve the aforementioned object, the present invention further provides a touch display panel, which has a touch screen and a capacitive fingerprint sensing device, and the capacitive fingerprint sensing device has:

a capacitive sensor array located in a fingerprint sensing area, performing a fingerprint scanning operation on the fingerprint sensing area in an active mode, stopping the fingerprint scanning operation in a first phase of a sleep mode, and performing a touch detection operation on a partial area of the fingerprint sensing area in a second stage of the sleep mode to generate a second wake-up signal;

At least one capacitance sensing circuit is distributed in at least one periphery of the fingerprint sensing area, each of the capacitance sensing circuits has a charge-to-voltage circuit and a comparator, wherein, in the first stage, the charge-to-voltage circuit is generating a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a first wake-up signal; and

a control unit for driving the capacitive sensor array to perform the touch when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period A detection operation is performed to generate the second wake-up signal, and when the second wake-up signal exhibits an active state, the capacitive sensor array enters the working mode.

In one embodiment, the capacitive sensor array has a plurality of fingerprint detection circuits, each of the fingerprint detection circuits has a charge-to-voltage circuit to generate an output voltage according to a partial fingerprint, and an analog The digital converter generates a digital output value according to the output voltage.

In one embodiment, the fingerprint sensing area is a square area.

In one embodiment, the capacitive fingerprint sensing device has a substrate for carrying the capacitive sensor array, the at least one capacitive sensing circuit and the control unit.

In one embodiment, the number of the fingerprint detection circuits is greater than the number of the capacitance sensing circuits.

In a possible embodiment, the display of the touch screen can be a liquid crystal display, a light emitting diode display, a mini light emitting diode (Mini-LED) bulk display, a micro light emitting diode (Micro-LED) display, a quantum dot display Light Emitting Diode (Q-LED) Display or Organic Light Emitting Diode Display.

In order to achieve the aforementioned object, the present invention further provides an information processing device, which has a central processing unit and the aforementioned touch display panel, wherein the central processing unit is used for communication with the control unit.

In a possible embodiment, the information processing device may be a smart phone, a portable computer, a vehicle-mounted computer or an access control device.

In order to enable your examiners to further understand the structure, features and purposes of the present invention, the accompanying drawings and detailed descriptions of preferred specific embodiments are as follows.

Please refer to FIG. 1 , which is a schematic diagram of an embodiment of the capacitive fingerprint sensing device of the present invention. As shown in FIG. 1 , a capacitive fingerprint sensing device 100 has a capacitive sensor array 110 , at least one capacitive sensing circuit 120 and a control unit 130 .

The capacitive sensor array 110 is located in a fingerprint sensing area, which performs a fingerprint scanning operation on the fingerprint sensing area in an active mode, stops the fingerprint scanning operation in a first phase of a sleep mode, and In a second stage of the sleep mode, a touch detection operation is performed on a partial area of the fingerprint sensing area to generate a second wake-up signal V _WK2 .

At least one capacitance sensing circuit 120 is distributed on at least one periphery of the fingerprint sensing area, and each capacitance sensing circuit 120 has a detecting circuit 121 and a sensing electrode 122 . Please refer to FIG. 2 , which shows a circuit diagram of an embodiment of the detection circuit 121 of FIG. 1 . As shown in FIG. 2, the detection circuit 121 has a charge-to-voltage circuit 121a and a comparator 121b, wherein, in the first stage, the charge-to-voltage circuit 121a generates a voltage signal _Vs according to a touch operation, and The comparator 121b compares the voltage signal V _S according to a reference voltage V _REF to generate a first wake-up signal V _WK1 , wherein when the first wake-up signal V _WK1 exhibits an active state, the capacitive sensor is made The array 110 enters the second phase, and the capacitive sensor array 110 also enters the second phase when the first wake-up signal V _WK1 exhibits an inactive state for more than a predetermined period.

The control unit 130 is coupled to the first wake-up signal V _WK1 when the first wake-up signal V _WK1 exhibits the active state, and when the first wake-up signal V _WK1 exhibits an inactive state for more than a predetermined period of time A first enable signal EN1 is output to drive the capacitive sensor array 110 to enter the second stage, and when the second wake-up signal V _WK2 is received, a second enable signal EN2 is output to drive the capacitor The sensor array 110 enters this mode of operation.

In addition, the capacitive sensor array 110 has a plurality of fingerprint detection circuits. Please refer to FIG. 3 , which shows a circuit diagram of one embodiment of each fingerprint detection circuit of the capacitive sensor array 110 of FIG. 1 . As shown in FIG. 3, a fingerprint detection circuit 111 has a sensing capacitor 111a, a charge-to-voltage circuit 111b, and an analog-to-digital converter 111c, wherein the charge-to-voltage circuit 111b is a part of the sensing capacitor 111a by pressing The fingerprint generates an output voltage V _FP , and the analog-to-digital converter 111c generates a digital output value D _OUT according to the output voltage V _FP under the control of a clock signal CLK.

In addition, the fingerprint sensing area may be a square area.

In addition, the capacitive fingerprint sensing device 100 has a substrate (not shown in the figure) to carry the capacitive sensor array 110 , the at least one capacitive sensing circuit 120 and the control unit 130 .

In addition, the number of the fingerprint detection circuits 111 is greater than the number of the capacitance sensing circuits 120 .

That is, the capacitive fingerprint sensing device of the present invention can first use the capacitive sensing circuit 120 to provide a touch event prediction function under low power consumption, and then use the fingerprint detection circuit 111 to provide a pre-judgment function of a touch event. The provided touch sensing function confirms the touch event; or when the capacitive sensing circuit 120 does not detect any touch event for a predetermined period of time, the fingerprint detection circuit 111 provides a touch sensing function to confirm Whether there is any touch event, so that a fingerprint scanning procedure can be executed under the condition of saving power consumption and no misjudgment.

According to the above description, the present invention further provides a wake-up method for a capacitive fingerprint sensing device. Please refer to FIG. 4 , which shows a flowchart of an embodiment of a wake-up method for a capacitive fingerprint sensing device of the present invention. As shown in FIG. 4 , the method includes: generating a first wake-up signal (step a) according to a sensing result of at least one capacitive sensing circuit located in at least one periphery of a capacitive sensor array (step a); presenting an active state, and driving a local area of the capacitive sensor array to perform a touch detection operation to generate a second wake-up signal when the first wake-up signal is in an inactive state for more than a predetermined period (step b); and using a control unit to drive the capacitive sensor array to enter a working mode to perform a fingerprint scanning operation when the second wake-up signal is detected to be in an active state (step c).

According to the above description, the present invention further provides a touch display panel. Please refer to FIG. 5 , which shows a block diagram of an embodiment of the touch display panel of the present invention. As shown in FIG. 5, a touch display panel 200 has a touch screen 210 and a capacitive fingerprint sensing device 220, wherein the capacitive fingerprint sensing device 220 is realized by the capacitive fingerprint sensing device 100, and the touch The display of the control screen 210 can be a liquid crystal display, a light emitting diode display, a mini light emitting diode (Mini-LED) bulk display, a micro light emitting diode (Micro-LED) display, a quantum dot light emitting diode (Q-LED) display ) displays or organic light emitting diode displays.

In addition, according to the above description, the present invention further discloses an information processing device. Please refer to FIG. 6 , which shows a block diagram of an embodiment of the information processing apparatus of the present invention. As shown in FIG. 6, an information processing device 300 has a central processing unit 310 and a touch display panel 320, wherein the touch display panel 320 is realized by the touch display panel 200 (which has the control unit 130). , and the central processing unit 310 is used to communicate with the control unit 130 .

In addition, in a possible embodiment, the information processing device 300 may be a smart phone, a portable computer, a vehicle-mounted computer or an access control device.

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

1. The wake-up method of the capacitive fingerprint sensing device of the present invention can provide a first-stage wake-up function with low power consumption by arranging capacitive sensing circuits around a fingerprint sensing area.

2. The wake-up method of the capacitive fingerprint sensing device of the present invention can detect a touch event in the capacitive sensing circuit, and two situations when the capacitive sensing circuit does not detect any touch event for more than a predetermined period of time In the following, a second-stage wake-up function is provided by detecting a plurality of sensing electrodes in a central area of the fingerprint sensing area, so that a fingerprint scanning procedure can be executed without power consumption and no misjudgment.

What is disclosed in this case is a preferred embodiment, and any partial changes or modifications that originate from the technical ideas of this case and are easily inferred by those who are familiar with the art are within the scope of the patent right of this case.

To sum up, regardless of the purpose, means and effect of this case, it shows that it is completely different from the conventional technology, and its first invention is suitable for practical use, and indeed meets the patent requirements of the invention. Society is to pray for the best.

100: Capacitive Fingerprint Sensing Device 110: Capacitive sensor array 111: Fingerprint detection circuit 111a: Sensing Capacitance 111b: Charge-to-Voltage Circuits 111c: Analog-to-digital converters 120: Capacitive sensing circuit 121: Detection circuit 121a: Charge-to-Voltage Circuits 121b: Comparator 122: Sensing electrode 130: Control unit 200: touch display panel 210: Touch screen 220: Capacitive Fingerprint Sensing Device 300: Information processing device 310: Central Processing Unit 320: touch display panel Step a: generating a first wake-up signal according to a sensing result of at least one capacitive sensing circuit located at at least one periphery of a capacitive sensor array Step b: driving a local area of the capacitive sensor array to perform a touch detection operation when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period to generate a second wake-up signal Step c: use a control unit to drive the capacitive sensor array into a working mode to perform a fingerprint scanning operation when the second wake-up signal is detected to be in an active state

FIG. 1 is a schematic diagram of an embodiment of a capacitive fingerprint sensing device of the present invention. FIG. 2 is a circuit diagram illustrating an embodiment of a detection circuit of the capacitive fingerprint sensing device of FIG. 1 . FIG. 3 is a circuit diagram illustrating an embodiment of each fingerprint detection circuit of the capacitive sensor array of the capacitive fingerprint sensing device of FIG. 1 . FIG. 4 is a flowchart illustrating an embodiment of a wake-up method for a capacitive fingerprint sensing device of the present invention. FIG. 5 is a block diagram illustrating an embodiment of the touch display panel of the present invention. FIG. 6 is a block diagram illustrating an embodiment of the information processing apparatus of the present invention.

Step a: generating a first wake-up signal according to a sensing result of at least one capacitive sensing circuit located at at least one periphery of a capacitive sensor array

Step b: driving a local area of the capacitive sensor array to perform a touch detection operation when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period to generate a second wake-up signal

Step c: use a control unit to drive the capacitive sensor array into a working mode to perform a fingerprint scanning operation when the second wake-up signal is detected to be in an active state

Claims (14)

A wake-up method for a capacitive fingerprint sensing device, comprising: generating a first wake-up signal according to a sensing result of at least one capacitive sensing circuit located at at least one periphery of a capacitive sensor array; When the first wake-up signal is in an active state, and when the first wake-up signal is in an inactive state for more than a predetermined period, a local area of the capacitive sensor array is driven to perform a touch detection operation to generate a touch detection operation. a second wake-up signal; and When the second wake-up signal is in an active state, the capacitive sensor array is brought into a working mode to perform a fingerprint scanning operation. A capacitive fingerprint sensing device, which has: a capacitive sensor array located in a fingerprint sensing area, performing a fingerprint scanning operation on the fingerprint sensing area in an active mode, stopping the fingerprint scanning operation in a first phase of a sleep mode, and performing a touch detection operation on a partial area of the fingerprint sensing area in a second stage of the sleep mode to generate a second wake-up signal; At least one capacitance sensing circuit is distributed in at least one periphery of the fingerprint sensing area, each of the capacitance sensing circuits has a charge-to-voltage circuit and a comparator, wherein, in the first stage, the charge-to-voltage circuit is generating a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a first wake-up signal; and a control unit for driving the capacitive sensor array to perform the touch when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period A detection operation is performed to generate the second wake-up signal, and when the second wake-up signal exhibits an active state, the capacitive sensor array enters the working mode. The capacitive fingerprint sensing device of claim 2, wherein the capacitive sensor array has a plurality of fingerprint detection circuits, and each of the fingerprint detection circuits has the charge-to-voltage circuit An output voltage is generated according to a partial fingerprint, and an analog-to-digital converter is used to generate a digital output value according to the output voltage. The capacitive fingerprint sensing device as described in claim 2, wherein the fingerprint sensing area is a square area. The capacitive fingerprint sensing device as described in item 2 of the patent application scope has a substrate to carry the capacitive sensor array, the at least one capacitive sensing circuit and the control unit. The capacitive fingerprint sensing device of claim 3, wherein the number of the fingerprint detection circuits is greater than the number of the capacitive sensing circuits. A touch display panel has a touch screen and a capacitive fingerprint sensing device, the capacitive fingerprint sensing device has: a capacitive sensor array located in a fingerprint sensing area, performing a fingerprint scanning operation on the fingerprint sensing area in an active mode, stopping the fingerprint scanning operation in a first phase of a sleep mode, and performing a touch detection operation on a partial area of the fingerprint sensing area in a second stage of the sleep mode to generate a second wake-up signal; At least one capacitance sensing circuit is distributed in at least one periphery of the fingerprint sensing area, each of the capacitance sensing circuits has a charge-to-voltage circuit and a comparator, wherein, in the first stage, the charge-to-voltage circuit is generating a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a first wake-up signal; and a control unit for driving the capacitive sensor array to perform the touch when the first wake-up signal is in an active state and when the first wake-up signal is in an inactive state for more than a predetermined period A detection operation is performed to generate the second wake-up signal, and when the second wake-up signal exhibits an active state, the capacitive sensor array enters the working mode. The touch display panel of claim 7, wherein the capacitive sensor array has a plurality of fingerprint detection circuits, and each of the fingerprint detection circuits has the charge-to-voltage circuit to A partial fingerprint generates an output voltage, and an analog-to-digital converter generates a digital output value according to the output voltage. The touch display panel of claim 7, wherein the fingerprint sensing area is a square area. The touch display panel of claim 7, wherein the capacitive fingerprint sensing device has a substrate for carrying the capacitive sensor array, the at least one capacitive sensing circuit and the control unit. The touch display panel of claim 8, wherein the number of the fingerprint detection circuits is greater than the number of the capacitance sensing circuits. The touch display panel as described in claim 7, wherein the display of the touch panel is composed of a liquid crystal display, a light emitting diode display, a mini light emitting diode (Mini-LED) bulk display, a micro light emitting diode A display selected from the group consisting of a bulk (Micro-LED) display, a quantum dot light-emitting diode (Q-LED) display and an organic light-emitting diode display. An information processing device has a central processing unit and the touch display panel according to any one of the claims 7 to 12 of the application scope, wherein the central processing unit is used for communication with the control unit. The information processing device described in item 13 of the scope of the application is a device selected from the group consisting of a smart phone, a portable computer, a vehicle-mounted computer and an access control device.

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