TWI777209B - Fingerprint sensing apparatus - Google Patents

Abstract

A fingerprint sensing apparatus includes a plurality of fingerprint sensing electrodes, a plurality of data lines respectively sandwiched by a first capacitance-shielding wire and a second capacitance-shielding wire, a fingerprint sensing circuit including a driver circuit with a gain larger than zero or equal to zero. During fingerprint sensing, the fingerprint sensing circuit sends a capacitance-exciting signal to a selected fingerprint sensing electrode, receiving a fingerprint sensing signal from the selected fingerprint sensing electrode, processing fingerprint sensing signal with the driver circuit into a capacitance-eliminating signal and applying the capacitance-eliminating signal to the first capacitance-shielding wire and the second capacitance-shielding wire respectively. The capacitance between the first/second capacitance-shielding wire and the corresponding data line can be greatly reduced because the voltages at the first/second capacitance-shielding wire same phase as that of corresponding data line, thus greatly enhance the accuracy of the fingerprint sensing apparatus.

Description

Fingerprint Identification Device

The present invention relates to a fingerprint identification device, in particular to a fingerprint identification device with a capacity-removing shielding wire.

Due to the rise of e-commerce and the rapid development of remote payment, the commercial demand for biometric identification is rapidly expanding, especially fingerprint identification as the preferred technology. When the bezel-less mobile display device has become a trend, the fingerprint recognition in the display screen has become a popular target. Solutions such as ultrasonic or under-screen optical detection have various problems such as high cost and difficulty in alignment, which are difficult to popularize. Only the capacitive fingerprint recognition technology that uses TFT technology to set the sensing electrodes and selection switches on the protective glass is economical and economical. Affordable. However, the thickness of the protective glass is hundreds of μm , so that the sensing signal is extremely small. In addition, the data line is several centimeters long, and its area is much larger than that of a single sensing electrode, and the distance between the data line and the data line is only a few μm. The crosstalk interference is serious. The traditional method of isolating conductive electrodes to ground to block noise will generate a huge self-capacitance, causing the tiny induction signal to disappear into the invisible, which is nothing but worse. Therefore, how to solve the various noises sensed on the data line has become an urgent problem to be solved.

One objective of the present invention is to improve the above-mentioned disadvantages of various noises induced by data lines in the prior art.

In order to achieve the above object, the present invention provides a fingerprint identification device, comprising: a substrate; a fingerprint electrode layer including a plurality of fingerprint sensing electrodes; a transistor switch layer including: a plurality of transistors A switch group, the transistor switch groups are in a one-to-one correspondence with the fingerprint sensing electrodes; a plurality of data lines, each of which corresponds to a first capacitance elimination shielding line and a second capacitance elimination shielding line , so that the first anti-capacity shielding wire and the second anti-capacity shielding wire sandwich a corresponding data line; the first anti-capacity shielding wire is located between the corresponding data line and a finger to be tested to exclude the finger to be tested Influence on the corresponding data line; a fingerprint detection circuit, comprising a capacitive excitation signal source and a driving circuit, wherein the gain of the driving circuit is greater than or equal to zero; wherein the fingerprint detection circuit passes through the plurality of transistor switch groups. One of them transmits a capacitive excitation signal to a selected fingerprint sensing electrode, and then inputs a fingerprint sensing signal from the selected fingerprint sensing electrode through the corresponding data line, and processes the fingerprint sensing signal through the driving circuit to output the same fingerprint as the fingerprint. A capacitance canceling shielding signal in the same phase of the sensing signal is transmitted, and the capacitance canceling shielding signal is transmitted to the first and second capacitance canceling shielding lines corresponding to the corresponding data lines for fingerprint detection operation.

In the fingerprint identification device of the present invention, since the first capacitance elimination shielding line and the second capacitance elimination shielding line and their corresponding data lines have the same phase voltage, the capacitance value between them can be reduced, and the measurement accuracy of the fingerprint identification device is improved.

10: Fingerprint identification device

100: Substrate

110: Fingerprint electrode layer

112: Fingerprint sensing electrode

150A: first insulating layer

150B: Second insulating layer

150C: Third insulating layer

140A: The first capacitance elimination shielding wire

140B: The second capacitance elimination shielding wire

A1, A2, A3: drive circuit

130, 21L1, 21L2, 21L3: Data line

132: virtual data line

11L1, 21L1~21L3, 22L1~22L3, 23L1~23L3, 1mL1, 2mL1~2mL3, 2nL1~2nL3: Data line

1Y1~1Y3~8Y1~8Y3: Gate line

C1: first capacitor

C2: second capacitor

Cfse: Fingerprint Sensing Capacitor

Cfdl, Csedl1, Csedl2...Csedln, Cfse1~Cfsen, Cfsem, Cdl: Capacitor

Cself: Self Capacitance

SE: Fingerprint Sensing Electrode

SEm, SEm1, SEm2: Selected fingerprint sensing electrodes

SE1~SEn: Unselected fingerprint sensing electrodes

W1,W2,W3: width

200: Fingerprint/touch detection circuit

210: First Power

212: First Ground

230: Capacitive excitation signal source

220A: First Amplifier

220B: Second amplifier

220C: Third Amplifier

SW1: The first switch

SW2: Second switch

VS: Fingerprint sensor signal

VE: Capacitor eliminates shading signal

300: Display control circuit

310: Second Power

312: Second ground

400: display screen

400A: touch display area

400B: Fingerprint detection and touch display area

A11..A1n...Am1..Amn: Fingerprint sensing electrodes

A, B, C: Fingerprint detection and touch display unit

D,E,F,G,H,I,J,K,L: touch sensing electrodes

FIGS. 1A to 1C are theoretical schematic diagrams respectively illustrating the fingerprint identification device with the capacity-reducing shielding line of the present invention.

FIG. 2 is a schematic diagram illustrating the influence of data lines on touch capacitance detection in a conventional fingerprint identification device.

FIG. 3 is another schematic diagram illustrating the influence of data lines on touch capacitance detection in a conventional fingerprint identification device.

FIG. 4 is a schematic diagram illustrating the improvement of touch capacitance detection by using a capacitance-removing shield line according to the present invention.

FIG. 5 is a schematic diagram illustrating the distribution of the touch display area and the fingerprint detection and touch display area in the display screen.

FIG. 6 is another schematic diagram illustrating the distribution of the touch display area and the fingerprint detection and touch display area in the display screen.

FIGS. 7A and 7B are circuit block diagrams illustrating a fingerprint identification device with de-capacitance shielding lines according to the present invention.

FIG. 8A and FIG. 8B are circuit block diagrams illustrating a fingerprint identification device with de-capacitance shielding lines according to the present invention.

FIG. 9 is a schematic diagram illustrating the distribution of the touch display area and the fingerprint detection and touch display area in the display screen.

FIG. 10 is a circuit block diagram illustrating a fingerprint identification device with an anti-capacity shielding line according to the present invention.

FIG. 11A is a schematic diagram illustrating the mutual capacitance of adjacent data lines.

FIG. 11B is a schematic diagram illustrating the self-capacitance of the data line.

FIG. 11C is a cross-sectional view illustrating the structure of the anti-capacity mask line of the fingerprint identification device with the anti-capacity mask line according to an embodiment of the present invention.

11D is a cross-sectional view illustrating the structure of the anti-capacity masking line of the fingerprint identification device with the anti-capacity masking line according to another embodiment of the present invention.

FIG. 11E is a cross-sectional view illustrating the structure of the anti-capacity mask line of the fingerprint identification device with the anti-capacity mask line according to another embodiment of the present invention.

For the detailed description and technical content of the present invention, please refer to the following detailed description and accompanying drawings. The accompanying drawings and detailed descriptions are only used for illustration and are not used to limit the present invention.

Referring to FIGS. 1A to 1C , which are theoretical schematic diagrams respectively illustrating the fingerprint identification device with the capacity-removing shielding line of the present invention. Referring to FIG. 1A , first anti-capacity shielding lines are respectively set up at positions adjacent to the data lines 130 For the 140A and the second anti-capacitance shielding line 140B, for example, a first anti-capacity shielding line 140A and a second anti-capacity shielding line 140B are respectively formed above and below the data line 130 . The above-mentioned so-called top and bottom can be, for example, the directions that the operator is used to when using the fingerprint identification device; however, it should be noted that according to the present invention, the first and second anti-capacity shielding lines 140A and 140B are set up as long as the data can be stored. When the lines 130 are sandwiched therein, for example, the first capacitance elimination shielding line 140A and the second capacitance elimination shielding line 140B may be located on the left and right sides of the data line 130 . In addition, if the noise of the data line 130 mainly comes from one side (for example, the lower side), the present invention can also only have a single anti-capacity shielding line, such as the one shown in FIG. 4, which can also achieve the effect of the present invention. The scope is not limited by this illustrated embodiment. As shown in FIG. 1A , the first anti-capacity shielding line 140A has a width W1 , the second anti-capacitive shielding line 140B has a width W2 , and the data line 130 has a width W3 . In the way that the data lines 130 are clamped in the upper and lower directions by the above-mentioned capacitance elimination shielding line, although the noise interference from the upper and lower sides can be shielded by the capacitance elimination shielding line, if the first capacitance elimination shielding line 140A and the second capacitance elimination shielding line 140A and the second capacitance elimination shielding line 140A and the second capacitance elimination shielding line If the shielding wire 140B is not properly biased, there will be a serious crosstalk problem. In other words, if one end of the first anti-capacitance shielding line 140A and the second anti-capacitance shielding line 140B is grounded, and one end of the data line 130 outputs the fingerprint sensing signal through the driving circuit (eg, an amplifier) A1, then the first anti-capacitance shielding line 140A and the A first capacitor C1 is generated between the data lines 130 , and a second capacitor C2 is generated between the second capacitance elimination shielding line 140B and the data line 130 . At this time, the first capacitor C1 and the second capacitor C2 will cause crosstalk of the fingerprint sensing signal, which affects the accuracy of fingerprint detection.

Referring to FIG. 1B , if the fingerprint sensing signal of the data line 130 (from the capacitance detection result of the selected fingerprint sensing electrode) is amplified by a driving circuit (such as an amplifier) A2 with a gain greater than or equal to zero into a capacitance-eliminating shading signal and then applied to the The first capacitance elimination shielding line 140A and the second capacitance elimination shielding line 140B, the first capacitance C1 generated between the first capacitance elimination shielding line 140A and the data line 130 is zero, and the second capacitance elimination shielding line 140B and The second capacitance C2 generated between the data lines 130 is also zero, so the establishment of the first capacitance elimination shielding line 140A and the second capacitance elimination shielding line 140B will not cause crosstalk of the output fingerprint sensing signal, nor will it affect the correct detection sex. The first anti-capacity shielding wire 140A and the second anti-capacity shielding wire 140B can further provide the shielding effect of the data line 130, that is, the fingerprint identification device with the anti-capacity shielding wire of the present invention can be used The fingerprint sensing capacitance Cfs (the detection result generated by the finger pressing on the selected fingerprint sensing electrode and outputted through the data line 130 ) can be correctly detected. In the above description, the gain of the driving circuit A2 is greater than or equal to zero; and when performing fingerprint detection, the gain of the driving circuit A2 is greater than zero (eg, 1) to amplify the fingerprint sensing signal in-phase.

Referring to FIG. 1C , if the fingerprint sensing signal of the data line 130 is amplified by a driving circuit (eg, an amplifier) A2 with a gain greater than or equal to zero into a capacitance-eliminating shielding signal, it is then applied to the first capacitance-eliminating shielding line 140A, and through another gain The drive circuit (such as an amplifier) A3 that is greater than or equal to zero amplifies a capacitance cancellation shielding signal and then applies it to the second capacitance cancellation shielding line 140B. Similarly, the first capacitance cancellation shielding line 140A and the data line 130 generate A capacitor C1 is zero, and the second capacitor C2 generated between the second capacitance elimination shielding line 140B and the data line 130 is also zero, so it will not cause crosstalk of the output fingerprint sensing signal, and will not affect the correct detection In other words, the fingerprint identification device with the capacitance-removing shielding line of the present invention can correctly detect the fingerprint sensing capacitance Cfs. Similarly, in the above description, the gains of the driving circuits A2 and A3 are greater than or equal to zero; and when performing fingerprint detection, the gains of the driving circuits A2 and A3 are greater than zero (for example, 1), so as to sense the fingerprint The signal is in-phase amplified.

Referring to FIG. 2 , the influence of the data lines on the touch capacitance detection in the conventional fingerprint identification device is illustrated. As shown in this figure, because the data line 130 generally has a very long extension length (relative to the fingerprint sensing electrode SE), for example, if the length of the data line 130 is 20,000um, even if its width is only 5um (less than the fingerprint sensing electrode SE) width of the sensing electrode SE), the area is still as high as 100,000um ² . Compared with the area of 50x50=2,500um ² of the fingerprint sensing electrode SE, it is 40 times more. In other words, if the data line 130 is adjacent to the fingerprint sensing electrode SE, the capacitance Cfdl between the user's finger and the data line 130 will be 40 times larger than the fingerprint sensing capacitance Cfse, which affects the detection accuracy.

Referring to FIG. 3 , the influence of the data lines on the touch capacitance detection in the conventional fingerprint identification device is illustrated. As shown in this figure, in addition to the influence of the data line 130, there are also capacitances Cfse1-Cfsen between the unselected fingerprint sensing electrodes SE1-SEn near the data line 130 and the finger, respectively; the unselected fingerprint sensing electrodes There are also capacitors Csed11-Csed1n between SE1-SEn and the data line 130. These capacitors Csed11-Csed1n also affect the sensing accuracy of the fingerprint sensing capacitor Cfse for the selected fingerprint sensing electrode SEm. What's more, the number of unselected fingerprint sensing electrodes SE1-SEn will be much larger than the number of selected fingerprint sensing electrodes SEm, resulting in more serious interference of the fingerprint sensing capacitor Cfse.

Referring to FIG. 4 , in order to illustrate, according to the present invention, using the capacitance-removing shielding line to improve the influence of the data line on the touch capacitance detection in the fingerprint identification device. Referring to this figure and referring to FIGS. 1B and 1C, if at least one anti-capacitance shielding line (such as the first anti-capacity shielding line 140A shown in the figure) is established for each data line 130, and the fingerprint sensing signal of the data line 130 is passed through A drive circuit (eg, an amplifier) A1 with a gain greater than or equal to zero generates a capacitance-eliminating shading signal with the same phase as the fingerprint sensing signal after amplification. The capacitance elimination shielding signal is then applied to the first capacitance elimination shielding line 140A, so that there is no capacitance (no potential difference) between the data line 130 and the first capacitance elimination shielding line 140A. Similarly, the capacitance cancellation masking signal can also be applied to the unselected fingerprint sensing electrodes SE1-SEn, so that there is no capacitance between the unselected fingerprint sensing electrodes SE1-SEn and the data line 130, so that the selected fingerprint can be detected more accurately. The fingerprint sensing capacitance Cfse of the sensing electrode SEm. In the embodiment of FIG. 4 , although only one capacitance elimination shielding line (ie, the first capacitance elimination shielding line 140A) is shown, and the capacitance elimination shielding signal is also applied to the unselected fingerprint sensing electrodes SE1-SEn; but according to this In another embodiment of the invention, a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B can be set up on the upper and lower sides of the data line 130, respectively, and the capacitance elimination shielding signal can be applied respectively in the manner similar to FIGS. 1B and 1C. to the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B to reduce interference. In the above description, the gain of the driving circuit A1 is greater than or equal to zero; and when performing fingerprint detection, the gain of the driving circuit A1 is greater than zero (for example, 1) to amplify the fingerprint sensing signal in-phase to generate capacitance Eliminate obscured signals.

Referring to FIG. 9 , it is a schematic diagram illustrating a touch display area 400A and a fingerprint detection and touch display area 400B in a display screen 400 . In the display screen 400 of a portable electronic product, there is usually a touch display area 400A for the user to perform touch input and display information; and a fingerprint detection area to Used for user identification. Since the resolution of fingerprint detection is greater than the touch resolution, according to an embodiment of the present invention, a plurality of fingerprint sensing electrodes A11..A1n...Am1..Amn can form a fingerprint detection and touch display unit A (ie as touch electrodes), and a plurality of fingerprint detection and touch display units A, B, C can form a fingerprint detection and touch display area 400B. The display screen 400 includes a touch display area 400A (including a plurality of touch sensing electrodes D, E . . . K, L) and a fingerprint detection and touch display area 400B. In the above description, the area of each touch sensing electrode is more than 50 times the area of the fingerprint sensing electrode, for example, 50-100 times, or 1000 times. Furthermore, because the density of the fingerprint sensing electrodes A11..A1n...Am1..Amn is much greater than the density of the touch sensing electrodes D, E....K, L, the fingerprint detection and touch display area 400B has a higher density. The linear density of data is high. In order to make the touch display area 400A and the fingerprint detection and touch display area 400B including the plurality of fingerprint sensing electrodes have the same or similar light transmittance, the touch display area 400A can be provided with a plurality of dummy data lines ( dummy data line) 132. The arrangement density of the imaginary data lines 132 can be, for example, similar to the arrangement density of the data lines 130 , and there is no need to connect any control circuit, so that the touch display area 400A and the fingerprint detection and touch display area 400B have the same or similar arrangement density The light transmittance increases the user's visual comfort during operation.

Referring to FIG. 5 , the touch area of the display screen 400 can be divided into upper and lower parts, for example, the upper touch display area 400A and the lower fingerprint detection and touch display area 400B. Referring to FIG. 9, the fingerprint detection and touch display unit A in the fingerprint detection and touch display area 400B is composed of a plurality of fingerprint sensing electrodes A11...A1n...Am1..Amn. Referring to FIGS. 1B and 1C again, a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B are respectively set up and down the data line 130 of the fingerprint sensing electrode, and the capacitance elimination shielding signal with the same phase as the fingerprint sensing signal is respectively applied to the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B to reduce interference. Therefore, the fingerprint detection and touch display area 400B of the display screen 400 of FIG. 5 has a more accurate detection result and has the effect of eliminating data line crosstalk.

Referring to FIG. 6 , the touch area of the display screen 400 also has a touch display area 400A and a fingerprint detection and touch display area 400B. However, compared with the embodiment of FIG. 5, the fingerprint detection and touch display area is The 400B has a smaller area. Similarly, referring to FIG. 9, the fingerprint detection and touch display unit A in the fingerprint detection and touch display area 400B is composed of a plurality of fingerprint sensing electrodes A11...A1n...Am1...Amn. Referring to FIGS. 1B and 1C again, a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B are respectively set up and down the data line 130 of the fingerprint sensing electrode, and the capacitance elimination shielding signal with the same phase as the fingerprint sensing signal is respectively applied to the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B to reduce interference. Therefore, the fingerprint detection and touch display area 400B of the display screen 400 in FIG. 6 also has a more accurate detection result and has the effect of eliminating data line crosstalk.

Referring to FIG. 7A , it is a circuit block diagram illustrating a fingerprint identification device with a capacitance-removing shielding line according to the present invention. The fingerprint identification device 10 is used in a self-capacitance structure and has a fingerprint/touch detection circuit 200 and a display control circuit 300, wherein the fingerprint/touch detection circuit 200 has a first power supply 210 and a first ground 212 ; And the display control circuit 300 has a second power supply 310 and a second ground 312, wherein the first ground 212 is a different ground from the second ground 312. In addition, the fingerprint/touch detection circuit 200 further includes a capacitive excitation signal source 230, a first amplifier 220A and a second amplifier 220B. The fingerprint identification device further has a first switch SW1 and a second switch SW2. Referring to FIG. 7A , in the fingerprint detection stage (or the touch detection stage, referring to FIG. 9 ), a plurality of fingerprint sensing electrodes A11..A1n...Am1..Amn can form a fingerprint detection and touch display unit A, for touch detection), the first switch SW1 and the second switch SW2 are turned on (closed), so that the capacitive excitation signal of the capacitive excitation signal source 230 can be transmitted to the selected sensing electrode SEm through the first switch SW1, In addition, the capacitive sensing signal on the sensing electrode SEm (reflecting the fingerprint detection result) can be transmitted to the first amplifier 220A through the second switch SW2, and processed into a fingerprint sensing signal VS through the first amplifier 220A. Furthermore, the fingerprint sensing signal VS is also passed through the second amplifier 220B (which is a driving circuit with a gain greater than or equal to zero) to form a capacitance canceling shading signal VE having the same phase as the fingerprint sensing signal VS. Referring to FIGS. 1B and 1C again, the upper and lower parts of the data lines 130 of the fingerprint sensing electrodes are respectively provided with a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B, and the fingerprint/touch detection circuit 200 respectively detects the capacitance elimination shielding signal VE Applied to the first anti-capacitance shield line 140A and the second anti-capacitance shield line 140B to reduce interference. Therefore, the fingerprint identification device with the anti-capacity shielding line of FIG. 7A can have a more accurate detection result, and has the effect of eliminating the crosstalk of the data line. In the above description, the gain of the second amplifier (driving circuit) 220B is greater than or equal to zero; and during fingerprint detection, the gain of the second amplifier 220B is greater than zero (for example, 1), so as to detect the fingerprint sensor signal. VS does non-inverting amplification to generate a capacitance-eliminating shading signal VE. In addition, in the fingerprint detection stage or the touch detection stage, the fingerprint/touch detection circuit 200 and the display control circuit 300 are only connected by a single physical wire, and the first ground 212 is different from the second ground 312 There is no common current loop between the first power supply 210 and the second power supply 310, which further improves the accuracy of fingerprint detection or touch detection.

Referring to FIG. 7B , it is a circuit block diagram illustrating the fingerprint identification device with the anti-capacity shielding line according to the present invention, wherein the fingerprint identification device is in a non-fingerprint detection stage (eg, display stage or signal communication stage). At this stage, the first switch SW1 and the second switch SW2 are turned off (opened), so that the capacitive excitation signal of the capacitive excitation signal source 230 is not transmitted to the selected sensing electrode SEm. Furthermore, at this stage, the fingerprint/touch detection circuit 200 and the display control circuit 300 can be electrically connected through two wires, so that the display control circuit 300 can charge the fingerprint/touch detection circuit 200, or The display control circuit 300 and the fingerprint/touch detection circuit 200 can communicate with each other.

Referring to FIG. 8A , it is a circuit block diagram illustrating a fingerprint identification device with a capacitance-removing shielding line according to the present invention. The fingerprint identification device 10 uses a mutual capacitance structure and has a fingerprint/touch detection circuit 200 and a display control circuit 300 , wherein the fingerprint/touch detection circuit 200 has a first power source 210 and a first ground 212 ; And the display control circuit 300 has a second power supply 310 and a second ground 312, wherein the first ground 212 is a different ground from the second ground 312. In addition, the fingerprint/touch detection circuit 200 further includes a capacitive excitation signal source 230, a first amplifier 220A and a second amplifier 220B. The fingerprint identification device further has a first switch SW1 and a second switch SW2. Referring to FIG. 8A , in the fingerprint detection stage or the touch detection stage, the first switch SW1 and the second switch SW2 are turned on (closed), so that the capacitive excitation signal of the capacitive excitation signal source 230 can pass through the first switch SW1 transmitted to the selected sensing electrode SEm1. Again Alternatively, the fingerprint/touch detection circuit 200 further receives the capacitive sensing signal (reacting the fingerprint detection result) from another selected sensing electrode SEm2 via the second switch SW2, and processes the capacitive sensing signal into a Fingerprint sensing signal VS. Furthermore, the fingerprint sensing signal VS is also passed through the second amplifier 220B (which is a driving circuit with a gain greater than or equal to zero) to form a capacitance cancellation shading signal VE having the same phase as the fingerprint sensing signal. Referring to FIGS. 1B and 1C again, the upper and lower parts of the data lines 130 of the fingerprint sensing electrodes are respectively provided with a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B, and the fingerprint/touch detection circuit 200 respectively detects the capacitance elimination shielding signal VE Applied to the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B to reduce interference. Therefore, the fingerprint identification device with the anti-capacity shielding line of FIG. 8A can have a more accurate detection result, and has the effect of eliminating the crosstalk of the data line. In the above description, the gain of the second amplifier (driving circuit) 220B is greater than or equal to zero; and during fingerprint detection, the gain of the second amplifier 220B is greater than zero (for example, 1), so as to detect the fingerprint sensor signal. Do the non-inverting amplification to generate the capacitance to eliminate the shading signal VE. In addition, in the fingerprint detection stage or the touch detection stage, the fingerprint/touch detection circuit 200 and the display control circuit 300 are only connected by a single physical wire, and the first ground 212 is different from the second ground 312 Therefore, there is no common current loop between the first power supply 210 and the second power supply 310, which further improves the accuracy of fingerprint detection or touch detection.

Referring to FIG. 8B , it is a circuit block diagram illustrating a fingerprint identification device with a capacitance-removing shielding line according to the present invention. The fingerprint identification device 10 is used in a self-capacitance/mutual-capacitance structure and has a fingerprint/touch detection circuit 200 and a display control circuit 300, wherein the fingerprint/touch detection circuit 200 has a first power supply 210 and a first A ground 212 ; and the display control circuit 300 has a second power source 310 and a second ground 312 , wherein the first ground 212 is a different ground from the second ground 312 . In addition, the fingerprint/touch detection circuit 200 further includes a capacitive excitation signal source 230, a first amplifier 220A and a second amplifier 220B. The fingerprint identification device further has a first switch SW1 and a second switch SW2. Referring to FIG. 8B , in the fingerprint detection stage, the first switch SW1 and the second switch SW2 are turned on (closed), so that the capacitive excitation signal of the capacitive excitation signal source 230 can be transmitted to the selected sensing electrodes SEm1 and SEm1 through the first switch SW1 another option The selected sensing electrode SEm2 (the capacitive excitation signal is amplified by the third amplifier 220C and then applied to another selected sensing electrode SEm2). Furthermore, the fingerprint/touch detection circuit 200 further receives the capacitance sensing signal (reflecting the fingerprint detection result) from another selected sensing electrode SEm2 through the second switch SW2, and processes the capacitance sensing signal through the first amplifier 220A. into a fingerprint sensing signal VS. Furthermore, the fingerprint sensing signal VS is also passed through the second amplifier 220B (which is a driving circuit with a gain greater than or equal to zero) to form a capacitance cancellation shading signal VE having the same phase as the fingerprint sensing signal. Referring to FIGS. 1B and 1C again, the upper and lower parts of the data lines 130 of the fingerprint sensing electrodes are respectively provided with a first capacitance elimination shielding line 140A and a second capacitance elimination shielding line 140B, and the fingerprint/touch detection circuit 200 respectively detects the capacitance elimination shielding signal VE Applied to the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B to reduce interference. Therefore, the fingerprint identification device with the anti-capacity shielding line shown in FIG. 8B can have a more accurate detection result, and has the effect of eliminating data line crosstalk. In the above description, the gain of the second amplifier (driving circuit) 220B is greater than or equal to zero; and during fingerprint detection, the gain of the second amplifier 220B is greater than zero (for example, 1), so as to detect the fingerprint sensor signal. Do the non-inverting amplification to generate the capacitance to eliminate the shading signal VE. In addition, in the fingerprint detection stage or the touch detection stage, the fingerprint/touch detection circuit 200 and the display control circuit 300 are only connected by a single physical wire, and the first ground 212 is different from the second ground 312 Therefore, there is no common current loop between the first power supply 210 and the second power supply 310, which further improves the accuracy of fingerprint detection or touch detection.

Referring to FIG. 10 , it is a circuit block diagram illustrating a fingerprint identification device with a capacitance elimination shielding line according to the present invention, wherein a plurality of fingerprint sensing electrodes and a plurality of corresponding transistor switch groups are displayed, that is, the plurality of transistor switch groups There is a one-to-one correspondence with the plurality of fingerprint sensing electrodes. Although FIG. 10 shows that the transistor switch group corresponding to each fingerprint sensing electrode has three transistor switches (such as thin film transistor switches), it should be noted that according to the present invention, each transistor switch group may also have only one transistor switch , the desired fingerprint sensing electrode selection function can be achieved.

Referring to FIG. 11A, in order to illustrate the schematic diagram of the mutual capacitance between adjacent data lines, there is a mutual capacitance Cdl between the adjacent data lines 21L1 and 21L2, and there is also a mutual capacitance between the adjacent data lines 21L2 and 21L3 Cdl. Because the distance between the data lines is very short, the mutual capacitance Cdl is much larger than the fingerprint sensing capacitance Cfs, which affects the accuracy of fingerprint sensing. Referring to FIG. 11B , which is a schematic diagram illustrating the self-capacitance of the data line, as shown in this figure, if the first anti-capacitance shielding line 140A or the adjacent conductor of the data line 130 is grounded, and the first anti-capacitance shielding line 140A (or the data line 130 is grounded) If the adjacent conductor is not properly biased, there will also be a large self-capacitance Cself between the data line 130 and the ground.

Referring to FIG. 11C , it is a cross-sectional view illustrating the structure of the anti-capacity mask line of the fingerprint identification device with the anti-capacity mask line according to an embodiment of the present invention. As shown in this figure, the fingerprint identification device may include a first anti-capacitance shielding line 140A, a first insulating layer 150A, a data line 130 ( 21L1 , 21L2 , 21L3 ), a second insulating layer 150B, and a second anti-capacitance layer from top to bottom. The shielding line 140B is accommodated. According to an embodiment of the present invention, the width of the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B may be greater than or equal to the width of the data line 130 . In addition, because the data lines 130 ( 21L1 , 21L2 , 21L3 ) are generally fabricated by etching the metal layers in an etching process to form spaces therebetween, there are gaps between the data lines 21L1 , 21L2 , and 21L3 . If the thicknesses of the first insulating layer 150A and the second insulating layer 150B are extremely thin (for example, less than 1 μm), the periphery of the data line 21L1 , the data line 21L2 , and the data line 21L3 are almost covered by the first capacitance elimination shielding line 140A and the second capacitance elimination The shielding line 140B is shielded, and after the first anti-capacitance shielding line 140A and the second anti-capacitance shielding line 140B are properly biased, the crosstalk, self-capacitance and mutual capacitance of the data lines can be eliminated.

Referring to FIG. 11D , it is a cross-sectional view illustrating the structure of the anti-capacity mask line of the fingerprint identification device with the anti-capacity mask line according to another embodiment of the present invention. As shown in this figure, the fingerprint identification device also includes a fingerprint electrode layer 110 (including a plurality of fingerprint sensing electrodes 112 ), a third insulating layer 150C, a first anti-capacity shielding wire 140A, a first insulating layer 150A, and a data wire from top to bottom. 130 ( 21L1 , 21L2 , 21L3 ), the second insulating layer 150B, the second anti-capacity shielding line 140B and the substrate 100 . However, in this embodiment, the width of the first anti-capacitance shielding line 140A and the second anti-capacity shielding line 140B is slightly larger than the width of the data line 130 . Therefore, both ends of the first capacitance elimination shielding wire 140A can be slightly sag, and together with the second capacitance elimination shielding wire 140B, cover the data line 130 . in this case In this case, the thicknesses of the first insulating layer 150A and the second insulating layer 150B can be made thicker, which can further reduce the self-capacitance and mutual capacitance of the data lines.

Referring to FIG. 11E , it is a cross-sectional view illustrating the structure of the anti-capacity masking line of the fingerprint identification device with the anti-capacity masking line according to another embodiment of the present invention. The illustrated embodiment is similar to the embodiment of FIG. 11D , but the fingerprint electrode layer 110 is formed directly on the substrate 100 . Similarly, the width of the first anti-capacity shielding line 140A and the second anti-capacity shielding line 140B is slightly larger than the width of the data line 130 . Therefore, both ends of the first capacitance elimination shielding wire 140A can be slightly sag, and together with the second capacitance elimination shielding wire 140B, cover the data line 130 . In this case, the thicknesses of the first insulating layer 150A and the second insulating layer 150B can be made thicker, which can further reduce the self-capacitance and mutual capacitance of the data lines. In the above-mentioned FIGS. 11D and 11E, the substrate 100 may be a protective glass for a display screen, a silicon substrate for an integrated circuit, or a polymer film. In the above-described embodiments, the data lines are metal conductive lines or transparent conductors, such as indium tin oxide (ITO); the fingerprint sensing electrodes are made of transparent conductive materials.

To sum up, the fingerprint identification device with the capacitance elimination shielding line proposed by the present invention can apply the capacitance elimination shielding signal to the first capacitance elimination shielding line and the second capacitance elimination shielding line respectively, and the first capacitance elimination shielding line can be used for the fingerprint identification device. The shielding wire and the second shielding wire clamp the data wire to reduce interference and have more accurate detection results.

However, the above descriptions are only the detailed descriptions and drawings of the preferred embodiments of the present invention, but the features of the present invention are not limited thereto, and are not intended to limit the present invention. The scope of the patent shall prevail, and all embodiments that are consistent with the spirit of the scope of the patent application of the present invention and similar variations thereof shall be included in the scope of the present invention. Anyone who is familiar with the art in the field of the present invention can easily think Changes or modifications can be covered by the following patent scope of the present case.

130: Data line

SEm: Selected fingerprint sensing electrode

SE1~SEn: Unselected fingerprint sensing electrodes

140A: The first capacitance elimination shielding wire

A1: drive circuit

Cfse: Fingerprint Sensing Capacitor

Cfdl, Csedl1, Csedl2...Csedln: Capacitance

Claims (14)

A fingerprint identification device, comprising: a substrate; a fingerprint electrode layer including a plurality of fingerprint sensing electrodes; a transistor switch layer including: a plurality of transistor switch groups, the plurality of transistor switch groups and the plurality of fingerprint sensing electrodes There is a one-to-one correspondence; a plurality of data lines, the plurality of data lines correspond to a first capacitance elimination shielding line and a second capacitance elimination shielding line, so that the first capacitance elimination shielding line and the second capacitance elimination shielding line A corresponding data line is sandwiched by the line; the first capacitance elimination shielding line is located between the corresponding data line and a finger to be tested; a fingerprint detection circuit includes a capacitive excitation signal source and an amplifier circuit, wherein the amplifier circuit is The gain is greater than or equal to zero; wherein the fingerprint detection circuit transmits a capacitive excitation signal to a selected fingerprint sensing electrode through one of the plurality of transistor switch groups, and inputs a signal from the selected fingerprint sensing electrode through the corresponding data line The fingerprint sensing signal is processed by the amplifier circuit to output a capacitance eliminating shading signal in the same phase as the fingerprint sensing signal, and the capacitance eliminating shading signal is sent to the first cancellation signal corresponding to the corresponding data line The shielding wire and the second shielding wire are used for fingerprint detection. The fingerprint identification device according to claim 1, wherein the second anti-capacity shielding line is located on a side of the corresponding data line facing away from the finger to be tested. The fingerprint identification device according to claim 1, wherein the line width of the first anti-capacity shielding line and the second anti-capacity shielding line is not less than the corresponding data line width. The fingerprint identification device of claim 1, wherein each transistor switch group includes at least one thin film transistor. The fingerprint identification device as claimed in claim 1, wherein the fingerprint detection circuit applies the capacitance cancellation masking signal to the fingerprint sensing electrodes around the corresponding data line during the fingerprint detection operation, so as to prevent the fingerprint sensing electrodes from passing through the surrounding fingerprint sensing electrodes. Other induction signals and noises connected to the corresponding data line. The fingerprint identification device of claim 1, wherein the fingerprint detection circuit is powered by a first power source, the fingerprint identification device further comprises a display screen powered by a second power source, and the plurality of fingerprint sensing electrodes are located at A fingerprint detection and touch display area of the display screen. The fingerprint identification device according to claim 6, wherein the plurality of fingerprint sensing electrodes are combined into a touch electrode. The fingerprint identification device of claim 7, wherein during a fingerprint detection operation or a touch detection operation, there is no common current loop between the first power source and the second power source. The fingerprint identification device according to claim 7, wherein a plurality of touch electrodes are arranged in a touch display area of the display screen for touch detection, and the area of each touch electrode is 50% of the area of the fingerprint sensing electrode times more. The fingerprint identification device according to claim 9, further comprising a plurality of imaginary data lines disposed in the touch display area, so that the touch display area and the fingerprint detection and touch control including the plurality of fingerprint sensing electrodes The display area has the same transmittance. The fingerprint identification device of claim 1, wherein the substrate is a protective glass for a display screen, a silicon substrate for an integrated circuit, or a polymer film. The fingerprint identification device according to claim 1, wherein the data lines are metal conductive lines or transparent conductors. The fingerprint identification device according to claim 1, wherein the fingerprint sensing electrodes are made of transparent conductive materials. The fingerprint identification device as claimed in claim 12, wherein the transparent conductor is indium tin oxide (ITO).

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