TWI782524B - Capacitive fingerprint sensing device and touch display device and information processing device having the same - Google Patents

Abstract

A capacitive fingerprint sensing device, which has: a capacitive sensor array, located in a fingerprint sensing area, which performs a fingerprint scanning operation on the fingerprint sensing area in a working mode, and in a sleep mode stop the fingerprint scanning operation; and at least one capacitive sensing circuit, each having a sensing electrode, a charge-to-voltage circuit and a comparator, the sensing electrode is located on a pixel spacing area in the capacitive sensor array, The charge-to-voltage circuit is located on a periphery of the fingerprint sensing area and is used to generate a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a wake-up signal; and a The control unit is used for driving the capacitive sensor array into the working mode when receiving the wake-up signal.

Description

Capacitive fingerprint sensing device, touch display device and information processing device having the capacitive fingerprint sensing device

The present invention relates to fingerprint verification, in particular to a capacitive fingerprint sensing device with power saving function.

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

A general mobile device will be provided with a capacitive fingerprint unlocking key at the bottom of the screen to facilitate the user to perform fingerprint unlocking operations. Since the capacitive fingerprint unlocking key only performs fingerprint scanning during the period when fingerprint verification is required, such as when powering on or conducting online financial transactions, the general capacitive fingerprint unlocking key will be in a dormant state 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 it to start the fingerprint verification process when a finger pressing operation is detected. The general method is to judge 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, because 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 a considerable amount of power, therefore, existing The energy-saving performance of the capacitive fingerprint unlocking key still has room for improvement.

In order to solve the above problems, there is an urgent need in the art for a novel capacitive fingerprint sensing device.

An object of the present invention is to disclose a capacitive fingerprint sensing device, which can provide a reliable touch wake-up function by arranging a capacitive sensing circuit in the pixel interval area of a fingerprint sensing area.

Another object of the present invention is to disclose a capacitive fingerprint sensing device, which can realize the capacitive sensing circuit through a charge-to-voltage circuit and a comparator, so that it can be operated at a low cost without an analog-to-digital converter. The way of power consumption provides reliable touch wake-up function.

In order to achieve the aforementioned purpose, a capacitive fingerprint sensing device is proposed, which has: a capacitive sensor array, located in a fingerprint sensing area, which performs a fingerprint scan on the fingerprint sensing area in an operating mode operation, and stop the fingerprint scanning operation in a sleep mode; at least one capacitive sensing circuit, each with a sensing electrode, a charge-to-voltage circuit and a comparator, the sensing electrode is located in the capacitive sensor array On a pixel interval area, the charge-to-voltage circuit is located on a periphery of the fingerprint sensing area and is used to generate a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a wake-up signal; and a control unit, configured to drive the capacitive sensor array into the working mode when receiving the wake-up signal.

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 analogously The digital converter generates a digital output value according to the output voltage.

In a possible embodiment, the shape of the sensing electrode may include at least one of a circle, an ellipse, a triangle, a square, a strip and a polygon.

In one embodiment, it further 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 capacitive sensing circuits.

To achieve the aforementioned purpose, the present invention further proposes 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 on a fingerprint The sensing area is to perform a fingerprint scanning operation on the fingerprint sensing area in a working mode, and stop the fingerprint scanning operation in a sleep mode; at least one capacitance sensing circuit, each having a sensing electrode, a charge-to-voltage circuit and a comparator, the sensing electrode is located on a pixel spacing area in the capacitive sensor array, the charge-to-voltage circuit is located on a periphery of the fingerprint sensing area and is used for a touch operation A voltage signal is generated, and the comparator compares the voltage signal according to a reference voltage to generate a wake-up signal; and a control unit is used to drive the capacitive sensor array into the Operating 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 analogously The digital converter generates a digital output value according to the output voltage.

In a possible embodiment, the shape of the sensing electrode may include at least one of a circle, an ellipse, a triangle, a square, a strip and a polygon.

In one embodiment, it further 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 capacitive sensing circuits.

In addition, the present invention also proposes an information processing device, which has a central processing unit and the aforementioned touch display panel, wherein the central processing unit is used for communicating with the control unit.

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

In order to enable your examiners to further understand the structure, features and purpose of the present invention, drawings and detailed descriptions of preferred specific embodiments are hereby attached.

Please refer to FIG. 1 , which is a schematic diagram of an embodiment of a 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, performs a fingerprint scanning operation on the fingerprint sensing area in a working mode, and stops the fingerprint scanning operation in a sleep mode.

At least one capacitive sensing circuit, each having a detection circuit 121 and a sensing electrode 122, the sensing electrode 122 is located on a pixel spacing area in the capacitive sensor array 110, the detection circuit 121 is located on the fingerprint A periphery of the sensing area is used to generate a voltage signal according to a touch operation, and compare the voltage signal according to a reference voltage to generate a wake-up signal V _WK . Please refer to FIG. 2 , which shows a circuit diagram of an embodiment of the detection circuit 121 in FIG. 1 . As shown in FIG. 2 , the detection circuit 121 has a charge-to-voltage circuit 121a and a comparator 121b, wherein the charge-to-voltage circuit 121a generates a voltage signal V _S according to a touch operation, and the comparator 121b is based on A reference voltage V _REF compares the voltage signal V _S to generate a wake-up signal V _WK .

In addition, the shape of the sensing electrode 122 may include at least one of a circle, an ellipse, a triangle, a square, a strip and a polygon.

After receiving the wake-up signal V _WK , the control unit 130 outputs an enable signal EN to drive the capacitive sensor array 110 into the working mode.

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 an embodiment of each fingerprint detection circuit of the capacitive sensor array 110 in 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 based on a part of the pressing sensing capacitor 111a 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 can 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 (121, 122) 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 (121, 122).

According to the above description, the capacitive fingerprint sensing device of the present invention can use the capacitive sensing circuit (121, 122) to provide a reliable touch wake-up function in the case of low power consumption, so as to wake up the capacitive sensing array 110 to perform a fingerprint scanning procedure.

According to the above description, the present invention further provides a touch display panel. Please refer to FIG. 4 , which shows a block diagram of an embodiment of the touch display panel of the present invention. As shown in FIG. 4, 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 panel 210 can be a liquid crystal display, a light-emitting diode display, a mini light-emitting diode (Mini-LED) display, a micro-light-emitting diode (Micro-LED) display, a quantum dot light-emitting diode (Q-LED) ) 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. 5 , which shows a block diagram of an embodiment of the information processing device of the present invention. As shown in FIG. 5, 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 can be a smart phone, a portable computer, a vehicle computer or an access control device.

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

1. The capacitive fingerprint sensing device of the present invention can provide a reliable wake-on-touch function by disposing a capacitive sensing circuit in the pixel interval area of a fingerprint sensing area.

2. The capacitive fingerprint sensing device of the present invention can implement the capacitive sensing circuit through a charge-to-voltage circuit and a comparator, so as to provide reliable Touch to wake function.

What is disclosed in this case is a preferred embodiment. For example, any partial changes or modifications derived from the technical ideas of this case and easily deduced by those who are familiar with the technology are within the scope of the patent right of this case.

To sum up, 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 it does meet the patent requirements of the invention. I implore your review committee to understand it clearly and grant a patent as soon as possible. Society is for the Most Prayer.

100: capacitive fingerprint sensing device

110: capacitive sensor array

111: Fingerprint detection circuit

111a: sensing capacitance

111b: Charge-to-voltage circuit

111c: Analog-to-Digital Converter

121: Detection circuit

121a: Charge-to-voltage circuit

121b: comparator

122: Induction 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

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 of an embodiment of the detection circuit of the capacitive fingerprint sensing device in FIG. 1 . FIG. 3 is a circuit diagram of an embodiment of each fingerprint detection circuit of the capacitive sensor array of the capacitive fingerprint sensing device in FIG. 1 . FIG. 4 shows a block diagram of an embodiment of the touch display panel of the present invention. FIG. 5 is a block diagram of an embodiment of an information processing device of the present invention.

100: capacitive fingerprint sensing device

110: capacitive sensor array

121: Detection circuit

122: Induction electrode

130: Control unit

Claims (12)

A capacitive fingerprint sensing device, which has: a capacitive sensor array, located in a fingerprint sensing area, which performs a fingerprint scanning operation on the fingerprint sensing area in a working mode, and in a sleep mode stop the fingerprint scanning operation; and at least one capacitive sensing circuit, each having a sensing electrode, a charge-to-voltage circuit and a comparator, the sensing electrode is located on a pixel spacing area in the capacitive sensor array, The charge-to-voltage circuit is located on a periphery of the fingerprint sensing area and is used to generate a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a wake-up signal; and a The control unit is used for driving the capacitive sensor array to enter the working mode when receiving a wake-up signal; wherein, each of the capacitive sensing circuits does not use an analog-to-digital converter. The capacitive fingerprint sensing device as described in item 1 of the scope of the patent application, wherein the capacitive sensor array has a plurality of fingerprint detection circuits, and each of the fingerprint detection circuits has a 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 described in item 1 of the scope of the patent application, wherein the shape of the sensing electrode includes a group consisting of a circle, an ellipse, a triangle, a square, a strip and a polygon Set at least one shape selected. According to the capacitive fingerprint sensing device described in claim 1 of the patent application, it further has a substrate for carrying the capacitive sensor array, the at least one capacitive sensing circuit and the control unit. In the capacitive fingerprint sensing device described in item 2 of the scope of the patent application, the number of the fingerprint detection circuits is greater than the number of the capacitive sensing circuits. A touch display panel, which 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, which is tied to a working performing a fingerprint scanning operation on the fingerprint sensing area in a mode, and stopping the fingerprint scanning operation in a sleep mode; and At least one capacitive sensing circuit, each having a sensing electrode, a charge-to-voltage circuit and a comparator, the sensing electrode is located on a pixel spacing area in the capacitive sensor array, the charge-to-voltage circuit is located on the On a periphery of the fingerprint sensing area and is used to generate a voltage signal according to a touch operation, and the comparator compares the voltage signal according to a reference voltage to generate a wake-up signal; and a control unit is used for receiving A wake-up signal drives the capacitive sensor array into the working mode; wherein each of the capacitive sensing circuits does not use an analog-to-digital converter. The touch display panel as described in item 6 of the scope of the patent application, wherein the capacitive sensor array has a plurality of fingerprint detection circuits, and each of the fingerprint detection circuits has a charge-to-voltage circuit according 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 described in item 6 of the scope of the patent application, wherein the shape of the sensing electrode includes a group consisting of a circle, an ellipse, a triangle, a square, a strip and a polygon Select at least one shape. The touch display panel as described in claim 6 of the patent application, wherein the capacitive fingerprint sensing device further has a substrate to carry the capacitive sensor array, the at least one capacitive sensing circuit and the control unit . The touch display panel as described in item 7 of the scope of the patent application, wherein the number of the fingerprint detection circuits is greater than the number of the capacitive sensing circuits. An information processing device has a central processing unit and the touch display panel as described in any one of items 6 to 10 of the scope of the patent application, wherein the central processing unit is used to communicate with the control unit. The information processing device described in item 11 of the scope of the patent application is a device selected from a group consisting of a smart phone, a portable computer, a vehicle-mounted computer and an access control device.

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