TWI781611B - Fingerprint collection circuit, fingerprint identification device and information processing device - Google Patents

Abstract

The present invention mainly discloses a fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels. The fingerprint collection circuit includes: a digital signal generating unit, a processing unit, and M×N switch units coupled between the M×N sensing pixels and the digital signal generating unit. Wherein, each switch unit is controlled by a row selection signal and a column selection signal, so that the level and width of the pulses of the M column selection signals and the N row selection signals are changed to partially or completely drive the switching unit. The capacitive sensor array has M×N sensing pixels. In this way, the fingerprint identification device including the fingerprint collection circuit of the present invention can simultaneously turn on multiple sensing pixels for fingerprint signal collection, thereby effectively increasing the amount of fingerprint signals and reducing the processing difficulty of the fingerprint unlocking algorithm.

Description

Fingerprint acquisition circuit, fingerprint identification device and information processing device

The invention relates to the related field of capacitive fingerprint collection technology, especially a fingerprint collection circuit applied in a fingerprint identification device.

It is known that capacitive fingerprint recognition devices have been widely used in various electronic products. FIG. 1 shows a block diagram of a conventional capacitive fingerprint recognition device. As shown in FIG. 1 , a conventional capacitive fingerprint identification device 1a mainly includes a capacitive sensor array 11a and a fingerprint acquisition circuit 12a, and the capacitive sensor array 11a includes M×N sensing pixels 111a . For example, the sensor array module 11a shown in FIG. 1 includes 8×8 sensing pixels 111a.

Further, FIG. 2 shows a block diagram of the fingerprint collection circuit 12a. As shown in Figure 2, the fingerprint collection circuit 12a includes M×N analog front-end units 121a, and M×N analog-to-digital conversion units 122a respectively coupled to the M×N analog front-end units 121a, and M×N A processing unit 123a coupled to the N analog-to-digital conversion units 122a, wherein each of the analog front-end units 121a is coupled to a sensing pixel 111a, and a current source 120a is coupled to both the sensing pixel 111a and the analog between front-end units 121a.

When performing fingerprint collection work, within a fingerprint collection cycle, the fingerprint collection circuit 12a uses its M×N analog front-end units 121a to sequentially (sequentially) detect an analog signal from each of the 8×8 sensing pixels 111a (that is, a voltage signal), and then the analog signal is converted into a digital signal by the corresponding analog-to-digital conversion unit 122a. Finally, the processing unit 123a uses an algorithm to process all the digital signals, so as to obtain a fingerprint collection image.

Practical experience points out that when the fingerprint collection circuit 12a of the prior art is used for fingerprint collection, it shows the disadvantage of poor collection efficiency. The main reason is that the fingerprint collection circuit 12a detects an analog signal from each of the M×N sensing pixels 111a sequentially (sequentially) within a fingerprint collection cycle, and cannot drive multiple sensing pixels 111a at the same time. detection pixels 111a, that is, analog signals are detected from multiple sensing pixels 111a at the same time.

It can be seen from the above description that there is an urgent need for a new type of fingerprint collection circuit in this field.

The main purpose of the present invention is to provide a fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels. The fingerprint collection circuit includes: a digital signal generating unit, a processing unit, and M×N switch units coupled between the M×N sensing pixels and the digital signal generating unit. Wherein, each switch unit is controlled by a row selection signal and a column selection signal, so that the level and width of the pulses of the M column selection signals and the N row selection signals are changed to partially or completely drive the switching unit. The capacitive sensor array has M×N sensing pixels. In this way, the fingerprint identification device including the fingerprint collection circuit of the present invention can simultaneously turn on multiple sensing pixels for fingerprint signal collection, thereby effectively increasing the amount of fingerprint signals and reducing the processing difficulty of the fingerprint unlocking algorithm.

To achieve the above object, the present invention proposes an embodiment of the fingerprint collection circuit, which is used to perform a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensing The sensor array includes a plurality of sensing blocks, and each of the sensing blocks contains j×k sensing pixels; the fingerprint collection circuit includes:

A digital signal generating unit with M×N analog signal receiving terminals and M×N digital signal output terminals;

a processing unit, coupled to the M×N digital signal output terminals; and

a plurality of first switch units having a first terminal, a second terminal, a third terminal and a control terminal;

Wherein, one analog signal receiving end is directly coupled to one sensing pixel of the sensing block, and (j×k)-1 first switch unit is connected to the sensing pixel by its first end and the sensing pixel. The remaining (j×k)-1 sensing pixels of the detection block are respectively coupled, and the (j×k)-1 first switch unit connects the second end of the (j×k)-1 said first switch unit with the M×N said The (j×k)-1 of the analog signal receiving ends are respectively coupled, and the (j×k)-1 first switch unit is directly connected to the analog signal receiving end by its third end coupling The sensing pixel is coupled, and the control terminals of (j×k)-1 first switch units are simultaneously coupled to a selection signal SEL;

Wherein, M, N, j, and k are all positive integers, 2≦j≦M, and 2≦k≦N.

In one embodiment, the digital signal generating unit includes:

M×N analog front-end units, respectively coupled to the M×N analog signal receiving ends; and

M×N analog-to-digital conversion units, respectively coupled to the M×N analog front-end units, and respectively coupled to the M×N digital signal output terminals;

Wherein, the analog front-end unit receives a sensing signal of the sensing pixel through the analog signal receiving end, and then correspondingly outputs an analog signal to the analog-to-digital conversion unit, so that the analog-to-digital conversion unit correspondingly outputs A digital signal is sent to the processing unit.

In one embodiment, when the selection signal has a first level, a first channel connected between the first end and the second end is formed inside the first switch unit, and the selection signal When it has a second level, a second channel communicating between the first end and the third end is formed inside the first switch unit.

In one embodiment, in the capacitive sensor array, the number of the sensing blocks is L=(M×N)/(j×k), where L is a positive integer, and the digital signal The generating unit receives the sensing signal from the sensing block through its j×k analog signal receiving ends.

In a feasible embodiment, the fingerprint collection circuit of the present invention further includes: further including: a plurality of second switch units controlled by the selection signal; wherein, in each group of j×k digital signals Among the output terminals, one of the digital signal output terminals directly outputs the digital signal to the processing unit, and the remaining (j×k)-1 digital signal outputs pass through (j×k)-1 digital signal output terminals. The second switch unit 125 transmits the digital signal to the processing unit.

In one embodiment, when the selection signal SEL has a first level, a channel is formed inside the second switch unit, so that the processing unit receives the digital signal from the digital signal output terminal through the channel. signal, and the channel is turned off when the selection signal SEL has a second level.

Moreover, the present invention also proposes another embodiment of the fingerprint collection circuit, which is used to perform a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensor The array includes a plurality of sensing blocks, and each of the sensing blocks includes j×k sensing pixels; the fingerprint collection circuit includes:

A digital signal generating unit with M×N/j×k analog signal receiving terminals and M×N/j×k digital signal output terminals;

A processing unit, coupled to M×N/j×k digital signal output terminals;

a plurality of first switch units having a first terminal, a second terminal, a third terminal and a control terminal; and

A switching unit with j×k signal receiving terminals, a signal output terminal and (j×k)-1 control terminals;

Wherein, the switching unit is coupled to one sensing pixel of the sensing block through one of its signal receiving ends, and (j×k)-1 first switching units are connected through their first ends are respectively coupled to the remaining (j×k)-1 sensing pixels of the sensing block, and (j×k)-1 first switching units are connected to the switching unit through the second end thereof The remaining (j×k)-1 signal receiving terminals are respectively coupled, and the (j×k)-1 first switch units are directly coupled with the third terminal coupling and the signal receiving terminal In the sensing pixel, (j×k)-1 control terminals of the first switching unit are coupled to a selection signal at the same time, and (j×k)-1 control terminals of the switching unit are also coupled to the The signal SEL is selected, and the signal output end of the switching unit is coupled to an analog signal receiving end.

Moreover, the present invention also proposes another embodiment of the fingerprint collection circuit, which is used to perform a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensor The array includes a plurality of sensing blocks, and each of the sensing blocks includes j×k sensing pixels; the fingerprint collection circuit includes:

A digital signal generating unit with M×N analog signal receiving terminals and M×N digital signal output terminals;

a processing unit, coupled to the M×N digital signal output terminals; and

A switch unit, including M×N switch units;

Wherein, in one sensing block, j×k sensing pixels are respectively coupled to j×k analog signal receiving terminals through j×k switching units, M, N , j, and k are all positive integers, 2≦j≦M, and 2≦k≦N;

Wherein, each of the switch units has a first terminal, a second terminal, a first control terminal and a second control terminal, the first terminal is coupled to the sensing pixel, and the second terminal is coupled to the The analog signal receiving end, the first control end is coupled to a first selection signal, and the second control end is coupled to a second selection signal.

In one embodiment, the digital signal generating unit includes:

M×N analog front-end units, respectively coupled to the M×N analog signal receiving ends; and

M×N analog-to-digital conversion units, respectively coupled to the M×N analog front-end units, and respectively coupled to the M×N digital signal output terminals;

Wherein, the analog front-end unit receives a sensing signal of the sensing pixel through the analog signal receiving end, and then correspondingly outputs an analog signal to the analog-to-digital conversion unit, so that the analog-to-digital conversion unit correspondingly outputs A digital signal is sent to the processing unit.

In one embodiment, when both the first selection signal and the second selection signal have a first level, a channel is formed inside the switch unit, so that the analog signal receiving end can transmit from the channel through the channel. The sensing block receives the sensing signal, and the channel is closed when both the first selection signal and the second selection signal have a second level.

Moreover, the present invention also discloses a fingerprint identification device, which is characterized in that it includes a capacitive sensor array and the fingerprint collection circuit of the present invention as mentioned above.

The present invention also discloses an information processing device, which has the fingerprint identification device of the present invention as mentioned above. And, in a feasible embodiment, the information processing device is selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, and access control devices. electronic device.

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

The purpose of the present invention is to propose a fingerprint collection circuit, which is applied to a capacitive fingerprint recognition chip, so that the capacitive fingerprint recognition chip can simultaneously turn on multiple sensing pixels for block-type fingerprint signal collection, effectively improving each time The collected fingerprint semaphore, thereby achieving the beneficial effect of reducing the processing difficulty of the fingerprint unlocking algorithm. In the case of applying the fingerprint acquisition circuit of the present invention, the capacitive fingerprint identification chip can determine the size of the block sensing pixels, and display the function of fingerprint signal acquisition supporting multiple DPIs, so that the capacitive fingerprint identification chip can efficiently Complete a series of tasks such as fingerprint image collection, comparison and unlocking.

first embodiment

FIG. 3 shows a first block diagram of a capacitive fingerprint recognition device including a fingerprint collection circuit of the present invention. As shown in FIG. 3 , the capacitive fingerprint identification device 1 mainly includes a capacitive sensor array 11 and a fingerprint acquisition circuit 12 of the present invention, and the capacitive sensor array 11 includes M×N sensing pixels 111 . For example, the sensor array module 11 shown in FIG. 3 includes 8×8 sensing pixels 111 .

FIG. 4 shows the first block diagram of the fingerprint collection circuit of the present invention. In the case of FIG. 3 , it should be understood that only 2×2 sensing pixels 111 in the capacitive sensor array 11 are depicted in FIG. 4 , which are respectively p00 , p01 , p10 and p11 . According to the design of the present invention, the fingerprint collection circuit 12 includes: a digital signal generating unit 120, a processing unit 123, and a plurality of first terminals with a first terminal, a second terminal, a third terminal and a control terminal. switch unit 124 . In more detail, the fingerprint collection circuit 12 of the present invention can determine the number of sensing pixels 111 covered by a sensing block according to different requirements. For example, a single sensing block contains j×k sensing pixels 111, at this time, the number of sensing blocks contained in the capacitive sensor array 11 is L=(M×N)/ (j×k). Wherein, M, N, j, k, and L are all positive integers, 2≦j≦M, and 2≦k≦N. In other words, the smallest sensing block contains 2×2 sensing pixels 111 .

As shown in FIG. 4 , the digital signal generating unit 120 has M×N analog signal receiving terminals and M×N digital signal output terminals, and the processing unit 123 is coupled to the M×N digital signal output terminals. According to the design of the present invention, in one sensing block, one analog signal receiving end is directly coupled to one sensing pixel 111 of the sensing block. In addition, (j×k)-1 first switch units 124 are respectively coupled with the first ends thereof to the remaining (j×k)-1 sensing pixels 111 of the sensing block, And (j×k)-1 of the first switch units 124 are respectively coupled to (j×k)-1 of the M×N analog signal receiving ends with the second terminals thereof. At the same time, (j×k)-1 first switch unit 124 is coupled to the sensing pixel 111 directly coupled to the analog signal receiving terminal through its third terminal, and (j×k)- A control terminal of one of the first switch units 124 is coupled to a selection signal SEL at the same time.

It is supplemented that, as shown in FIG. 4 , the digital signal generating unit 120 includes M×N analog front-end units 121 and M×N analog-to-digital conversion units 122, wherein M×N analog front-end units 121 and M×N The analog signal receiving ends are respectively coupled. Moreover, the M×N analog-to-digital conversion units 122 are respectively coupled to the M×N analog front-end units 121 , and are respectively coupled to the M×N digital signal output terminals. Moreover, FIG. 4 also shows a current source 12C coupled between the sensing pixel 111 and the analog front-end unit 121 . In terms of basic functions, the analog front-end unit 121 receives a sensing signal from the sensing pixel 111 through the analog signal receiving end, and then correspondingly outputs an analog signal to the analog-to-digital conversion unit 122, so that the analog The digital conversion unit 122 correspondingly outputs a digital signal to the processing unit 123 .

Continue to refer to FIG. 4, and please refer to FIG. 5 at the same time, which shows the second block diagram of the fingerprint collection circuit of the present invention. As shown in FIG. 4, when the selection signal SEL has a first level (such as SEL=0), the first switch unit 124 internally forms a first terminal connected between the first terminal and the second terminal. aisle. At this time, in the sensing block containing 2×2 sensing pixels 111, as shown in FIG. The sensing signal of the sensing pixel 111 is converted into a digital signal Vout01 by the digital signal generating unit 120, the sensing signal of the sensing pixel 111 of p10 is converted into a digital signal Vout10 by the digital signal generating unit 120, and the sensing signal of p11 The sensing signal of the pixel 111 is converted into a digital signal Vout11 by the digital signal generating unit 120 .

As shown in FIG. 5, when the selection signal SEL has a second level (such as SEL=1), the first switch unit 124 internally forms a second switch connected between the first terminal and the third terminal. aisle. At this time, in the sensing block containing 2×2 sensing pixels 111, as shown in FIG. The detection pixels 111 are connected in parallel with each other, so that the parallel detection signal is converted into a digital signal Vout00 by the digital signal generating unit 120 .

6 shows a first block diagram of a digital signal generating unit, a processing unit, and a sensing block of 2×2 sensing pixels, and FIG. 7 shows a digital signal generating unit, a processing unit, and a sensing block of 2×2 sensing pixels. The second block diagram of the measuring block. In a feasible embodiment, as shown in FIG. 4 and FIG. 6, the fingerprint collection circuit 12 of the present invention further includes: a plurality of second switch units 125 controlled by the selection signal SEL; wherein, in each group j Among the ×k digital signal output terminals, one digital signal output terminal directly outputs the digital signal to the processing unit 123, and the remaining (j×k)-1 digital signal outputs pass through ( j×k)—1 second switch unit 125 transmits the digital signal to the processing unit 123 . As shown in FIG. 4 and FIG. 6, when the selection signal SEL has a first level, a channel is formed inside the second switch unit 125, so that the processing unit 123 can output from the digital signal through the channel. terminal to receive the digital signal. At this time, in the sensing block containing 2×2 sensing pixels 111, as shown in FIG. 4 and FIG. The signal Vout01, the digital signal Vout10 of the sensing pixel 111 corresponding to p10, and the digital signal Vout11 of the sensing pixel 111 corresponding to p11 are respectively sent to the processing unit 123 through four different digital signal output terminals.

As shown in FIG. 5 and FIG. 7 , when the selection signal SEL has a second level (for example, SEL=1), the channel inside the second switch unit 125 is turned off. At this time, in the sensing block containing 2×2 sensing pixels 111, as shown in FIG. The detection pixels 111 are connected in parallel, so that the parallel detection signal is converted into a digital signal Vout00 by the digital signal generation unit 120 , and the digital signal Vout00 is sent to the processing unit 123 by one of the digital signal output terminals.

second embodiment

FIG. 8 shows a block diagram of a digital signal generation unit 120 , a processing unit 123 , a sensing block of 2×2 sensing pixels, and a first switching unit 127 . After comparing FIG. 8 with FIG. 5, it can be understood that according to the design shown in FIG. The method of adding the first switching unit 127 achieves the effect of using an analog front-end unit 121 and an analog-to-digital conversion unit 122 to process the sensing signal of a sensing block including j×k sensing pixels 111 . In other words, in the second embodiment, the fingerprint collection circuit 12 of the present invention includes: a digital signal generation unit 120 having L analog front-end units 121 and L analog-to-digital conversion units 122, a processing unit 123, a plurality of The first switch unit 124 has a first terminal, a second terminal, a third terminal and a control terminal, and L first switch units 127 . Wherein, the digital signal generating unit 120 has L (ie, M×N/j×k) analog signal receiving terminals and L digital signal output terminals, the processing unit 123 is coupled to the L digital signal output terminals, and The first switching unit 127 has j×k signal receiving terminals, one signal output terminal and (j×k)−1 control terminals.

In more detail, the first switching unit 127 is coupled to one of the sensing pixels 111 of the sensing block with one of its signal receiving ends, (j×k)-1 of the first switching unit 124 is respectively coupled to the remaining (j×k)-1 sensing pixels 111 of the sensing block with its first end, and (j×k)-1 first switching unit 124 is connected to The second end is respectively coupled to the remaining (j×k)-1 signal receiving ends of the first switching unit 127, and the (j×k)-1 first switching unit 124 uses its described The third end is coupled to the sensing pixel 111 directly coupled to the signal receiving end, and the control end of (j×k)-1 first switch unit 124 is simultaneously coupled to a selection signal SEL, and the first switch unit 124 is coupled to a selection signal SEL, and the first switch unit 124 The (j×k)−1 control terminals of a switching unit 127 are also coupled to the selection signal SEL.

It can be seen from FIG. 8 that the first switching unit 127 includes a plurality of switching elements 1271 . Moreover, for one sensing block, the number of configured switch elements 1271 is the same as the number of configured first switch units 124 . In this design, the selection signal has (j×k)-1 switch control bits, and the selection signal is SEL[n:0], where n=(j×k)-1. Taking j×k=2×2 as an example, the first switching unit 127 has four signal receiving terminals, one signal output terminal and three control terminals, and the selection signal is SEL[2:0], including bits SEL[ 2], bit SEL[1] and bit SEL[0]. Wherein, the first switching unit 127 includes three switching elements 1271, and each of the switching elements 1271 has a first terminal, a second terminal, a third terminal and a control terminal.

As shown in FIG. 8, the first end of the first switching element 1271 is used as a signal receiving end to couple to a sensing pixel 111 of the sensing block, and its second end is also used as a signal receiving end to couple to the first sensing pixel. The second end of a first switch unit 124 . On the other hand, the first end of the second switch element 1271 is used as a signal receiving end to couple to the second end of the first first switch unit 124, and its second end is also used as a signal receiving end to couple to the first The second ends of the three first switch units 124 . Moreover, the first end of the third switching element 1271 is coupled to the third end of the first switching element 1271, the second end thereof is coupled to the third end of the second switching element 1271, and the third end serves as the The signal output terminal of the first switching unit 127 is coupled to an analog signal receiving terminal of the digital signal generating unit 120 .

As shown in FIG. 8, the control terminal of the first first switch unit 124 is used as the first control terminal of the switch unit 127 to couple the selection signal to be controlled by the bit SEL[1]. The second first switch The control terminal of the unit 124 is used as the second control terminal of the switching unit 127 to couple the selection signal to be controlled by the bit SEL[1], and the control terminal of the third first switch unit 124 is used as the switching unit 127 The third control terminal is connected to the selection signal to be controlled by the bit SEL[0]. It should be noted that the control terminals of the three first switch units 124 are simultaneously coupled to the selection signal to be controlled by the bit SEL[2].

For example, when the selection signal SEL[2:0]=3'b100, the sensing signal of the sensing pixel 111 of p00 is finally converted into a digital signal Vout by the digital signal generating unit 120 . When the selection signal SEL[2:0]=3'b110, the sensing signal of the sensing pixel 111 of p01 is finally converted into a digital signal Vout by the digital signal generating unit 120. When the selection signal SEL[2:0]=3'b101, the sensing signal of the sensing pixel 111 of p10 is finally converted into a digital signal Vout by the digital signal generating unit 120. Moreover, when the selection signal SEL[2:0]=3'b111, the sensing signal of the sensing pixel 111 of p11 is finally converted into a digital signal Vout by the digital signal generating unit 120 . Further, when the selection signal SEL[2:0]=is 3'b000, the sensing signals of the four sensing pixels 111 (that is, the entire sensing block) of p00, p01, p10, and p11 are finally determined by the bit The signal generating unit 120 converts it into a digital signal Vout. Moreover, when the selection signal SEL[2:0]=is 3'b001, 3'b010 or 3'b011, the four sensing pixels 111 of p00, p01, p10, and p11 (that is, the sensing pixels in the sensing block 2×2 sensing pixels 111) are in a floating state.

third embodiment

FIG. 9 shows a second block diagram of a capacitive fingerprint recognition device including a fingerprint collection circuit of the present invention. As shown in FIG. 9 , the capacitive fingerprint identification device 1 mainly includes a capacitive sensor array 11 and the fingerprint collection circuit 12 of the present invention, and the capacitive sensor array 11 includes M×N sensing pixels 111 . In the second embodiment, the fingerprint collection circuit 12 of the present invention includes: a digital signal generating unit 120 , a processing unit 123 , and a second switching unit 126 of M×N switching units.

FIG. 10 shows a first structural diagram of 3×3 switch units and 3×3 sensing pixels. As shown in FIG. 10, in a sensing block containing 3×3 sensing pixels 111, j×k (ie, 3×3) sensing pixels 111 pass through j×k said switches. The unit 1261 is respectively coupled to j×k analog signal receiving terminals, M, N, j, and k are all positive integers, 2≦j≦M, and 2≦k≦N. Wherein, each of the switch units 1261 has a first terminal, a second terminal, a first control terminal and a second control terminal, the first terminal is coupled to the sensing pixel 111, and the second terminal is coupled to the sensing pixel 111. Connected to the analog signal receiving end, the first control end is coupled to a first selection signal Col_SEL, and the second control end is coupled to a second selection signal Row_SEL.

Therefore, the M×N switch units 1261 are coupled to N row selection signals (ie, the first selection signal Col_SEL) and M column selection signals (ie, the second selection signal Row_SEL). In this way, when both the first selection signal Col_SEL and the second selection signal Row_SEL have a first level (such as SEL=1), a channel is formed inside the switch unit 1261, so that the analog signal receiving end The sensing signal is received from the sensing block through the channel. Moreover, FIG. 11 shows a second structural diagram of 3×3 switch units and 3×3 sensing pixels. As shown in FIG. 11 , when both the first selection signal Col_SEL and the second selection signal Row_SEL have a second level (for example, SEL=0), the channel inside the switch unit 1261 is closed.

FIG. 12 is a timing diagram of three (ie, N) first selection signals Col_SEL and three (ie, M) second selection signals Row_SEL. As shown in Figure 11, by changing the level and width of the pulses of the M column selection signals (ie, the second selection signal) and the N row selection signals (ie, the first selection signal), in order to partially or All M×N sensing pixels 111 of the capacitive sensor array are driven. In this way, the fingerprint collection circuit 12 of the present invention can support simultaneous activation of multiple sensing pixels for fingerprint signal collection, thereby effectively increasing the amount of fingerprint signals and reducing the processing difficulty of the fingerprint unlocking algorithm.

Thus, the above has completely and clearly described a fingerprint collection circuit 12 of the present invention; and, through the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels. The fingerprint collection circuit includes: a digital signal generating unit, a processing unit, and M×N switch units coupled between the M×N sensing pixels and the digital signal generating unit. Wherein, each switch unit is controlled by a row selection signal and a column selection signal, so that the level and width of the pulses of the M column selection signals and the N row selection signals are changed to partially or completely drive the switching unit. The capacitive sensor array has M×N sensing pixels. In this way, the fingerprint identification device including the fingerprint collection circuit of the present invention can simultaneously turn on multiple sensing pixels for fingerprint signal collection, thereby effectively increasing the amount of fingerprint signals and reducing the processing difficulty of the fingerprint unlocking algorithm.

(2) The present invention also discloses a fingerprint identification device, which is characterized in that it includes a capacitive sensor array and the fingerprint collection circuit of the present invention as mentioned above.

(3) The present invention also provides an information processing device, which includes the fingerprint recognition device of the present invention as described above. And, in a feasible embodiment, the information processing device is selected from the group consisting of smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, and access control devices. electronic device.

It must be emphasized that what is disclosed in the above-mentioned case is a preferred embodiment, and all partial changes or modifications derived from the technical ideas of this case and easily deduced by those familiar with the technology are all inseparable from the patent of this case. category of rights.

To sum up, the purpose, means and efficacy of this case all show that it is very different from the conventional technology, and its first invention is practical, and indeed meets the patent requirements of the invention. I implore your review committee to be aware and grant a patent as soon as possible to benefit you. Society is for the Most Prayer.

1a: Capacitive fingerprint recognition device 11a: Capacitive sensor array 111a: sensing pixels 12a: Fingerprint collection circuit 120a: current source 121a: Analog front-end unit 122a: Analog-to-digital conversion unit 123a: processing unit 1: Capacitive fingerprint recognition device 11: Capacitive sensor array 111: Sensing pixels 12: Fingerprint acquisition circuit 12C: current source 120: Digital signal generating unit 121: Analog front-end unit 122: Analog-to-digital conversion unit 123: Processing unit 124: The first switch unit 125: the second switch unit 127: The first switching unit 126: Second switching unit 1261: switch unit 1271: switch element

FIG. 1 is a block diagram of a conventional capacitive fingerprint sensing device; 2 is a block diagram of a fingerprint collection circuit included in a conventional capacitive fingerprint sensing device; 3 is a first block diagram of a capacitive fingerprint identification device comprising a fingerprint collection circuit of the present invention; Fig. 4 is the first block diagram of the fingerprint collection circuit of the present invention; Fig. 5 is the second block diagram of the fingerprint acquisition circuit of the present invention; 6 is a first block diagram of a digital signal generating unit, a processing unit, and a sensing block of 2×2 sensing pixels; 7 is a second block diagram of a digital signal generation unit, a processing unit, and a sensing block of 2×2 sensing pixels; 8 is a block diagram of a digital signal generation unit, a processing unit, a sensing block of 2×2 sensing pixels, and a first switching unit; 9 is a second block diagram of a capacitive fingerprint recognition device comprising a fingerprint collection circuit of the present invention; FIG. 10 is a first structural diagram of 3×3 switch units and 3×3 sensing pixels; FIG. 11 is a second structural diagram of 3×3 switch units and 3×3 sensing pixels; and FIG. 12 is a timing diagram of three first selection signals and three second selection signals.

111: Sensing pixels

12: Fingerprint acquisition circuit

12C: current source

120: Digital signal generating unit

121: Analog front-end unit

122: Analog-to-digital conversion unit

123: Processing unit

124: The first switch unit

Claims (13)

A fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensor array includes a plurality of sensing blocks, and each of the The sensing block contains j×k sensing pixels; the fingerprint collection circuit includes: A digital signal generating unit with M×N analog signal receiving terminals and M×N digital signal output terminals; a processing unit, coupled to the M×N digital signal output terminals; and a plurality of first switch units having a first terminal, a second terminal, a third terminal and a control terminal; Wherein, one analog signal receiving end is directly coupled to one sensing pixel of the sensing block, and (j×k)-1 first switch unit is connected to the sensing pixel by its first end and the sensing pixel. The remaining (j×k)-1 sensing pixels of the detection block are respectively coupled, and the (j×k)-1 first switch unit connects the second end of the (j×k)-1 said first switch unit with the M×N said The (j×k)-1 of the analog signal receiving ends are respectively coupled, and the (j×k)-1 first switch unit is directly connected to the analog signal receiving end by its third end coupling The sensing pixel is coupled, and the control terminals of (j×k)-1 first switch units are simultaneously coupled to a selection signal; Wherein, M, N, j, and k are all positive integers, 2≦j≦M, and 2≦k≦N. The fingerprint collection circuit as described in Claim 1, wherein the digital signal generation unit includes: M×N analog front-end units, respectively coupled to the M×N analog signal receiving ends; and M×N analog-to-digital conversion units, respectively coupled to the M×N analog front-end units, and respectively coupled to the M×N digital signal output terminals; Wherein, the analog front-end unit receives a sensing signal of the sensing pixel through the analog signal receiving end, and then correspondingly outputs an analog signal to the analog-to-digital conversion unit, so that the analog-to-digital conversion unit correspondingly outputs A digital signal is sent to the processing unit. The fingerprint collection circuit according to claim 1, wherein, when the selection signal has a first level, a first channel connected between the first end and the second end is formed inside the first switch unit , and when the selection signal has a second level, a second channel connected between the first end and the third end is formed inside the first switch unit. The fingerprint acquisition circuit as described in claim 2, wherein, in the capacitive sensor array, the number of the sensing blocks is L=(M×N)/(j×k), where L is positive integer, and the digital signal generating unit receives the sensing signal from the sensing block through its j×k analog signal receiving terminals. The fingerprint collection circuit as described in claim 4 further includes: a plurality of second switch units controlled by the selection signal; wherein, in each group of j×k digital signal output terminals, one of the The digital signal output terminal directly outputs the digital signal to the processing unit, and the remaining (j×k)-1 digital signal outputs are transmitted through the (j×k)-1 second switch unit. The digital signal is sent to the processing unit. The fingerprint collection circuit according to claim 5, wherein when the selection signal has a first level, a channel is formed inside the second switch unit, so that the processing unit can obtain the digital signal from the digital signal through the channel. The output terminal receives the digital signal, and the channel is closed when the selection signal has a second level. A fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensor array includes a plurality of sensing blocks, and each of the The sensing block contains j×k sensing pixels; the fingerprint collection circuit includes: a digital signal generating unit with M×N analog signal receiving terminals and M×N digital signal output terminals; a processing A unit, coupled to M×N digital signal output terminals; and a switching unit, including M×N switching units; wherein, in one sensing block, j×k sensing pixels The j×k switching units are respectively coupled to the j×k analog signal receiving ends, M, N, j, and k are all positive integers, 2≦j≦M, and 2≦k≦N; Wherein, each of the switch units has a first terminal, a second terminal, a first control terminal and a second control terminal, the first terminal is coupled to the sensing pixel, and the second terminal is coupled to the The analog signal receiving end, the first control end is coupled to a first selection signal, and the second control end is coupled to a second selection signal. The fingerprint collection circuit as described in claim 7, wherein the digital signal generating unit includes: M×N analog front-end units, respectively coupled to M×N analog signal receiving terminals; and M×N analog-to-digital conversion units, respectively coupled to the M×N analog front-end units, and respectively coupled to the M×N digital signal output terminals; Wherein, the analog front-end unit receives a sensing signal of the sensing pixel through the analog signal receiving end, and then correspondingly outputs an analog signal to the analog-to-digital conversion unit, so that the analog-to-digital conversion unit correspondingly outputs A digital signal is sent to the processing unit. The fingerprint acquisition circuit as described in claim 7, wherein, when both the first selection signal and the second selection signal have a first level, a channel is formed inside the switch unit to make the analog signal The receiving end receives the sensing signal from the sensing block through the channel, and the channel is closed when both the first selection signal and the second selection signal have a second level. A fingerprint collection circuit for performing a fingerprint collection operation on a capacitive sensor array including M×N sensing pixels, wherein the capacitive sensor array includes a plurality of sensing blocks, and each of the The sensing block contains j×k sensing pixels; the fingerprint collection circuit includes: A digital signal generating unit with M×N/j×k analog signal receiving terminals and M×N/j×k digital signal output terminals; A processing unit, coupled to M×N/j×k digital signal output terminals; a plurality of first switch units having a first terminal, a second terminal, a third terminal and a control terminal; and A switching unit, having j×k signal receiving terminals, a signal output terminal, and (j×k)-1 control terminals; Wherein, one of the signal receiving ends of the switching unit is coupled to one of the sensing pixels of the sensing block, (j×k)-1 of the first switching units with their first ends and The remaining (j×k)-1 sensing pixels of the sensing block are respectively coupled, and the (j×k)-1 first switching unit is connected to the remaining switching unit by its second terminal. The (j×k)-1 signal receiving ends are respectively coupled, and the (j×k)-1 first switch units are directly coupled with the third end of the first switch unit and the signal receiving end In the sensing pixel, the (j×k)-1 control terminals of the first switching unit are coupled to a selection signal at the same time, and the (j×k)-1 control terminals of the switching unit are also coupled to the selection signal. signal, and the signal output terminal of the switching unit is coupled to one of the analog signal receiving terminals. A fingerprint identification device, which has the fingerprint collection circuit according to any one of claims 1-10. An information processing device having the fingerprint identification device as described in claim 11. The information processing device as described in Claim 12 is an electronic device selected from the group consisting of a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, and an access control device.

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