Fingerprint identification panel and a method for driving the same, and display apparatus

Provided is a fingerprint identification panel comprising multiple first electrode strips, multiple second electrode strips, a scanning device, a sensing signal providing device and an identification device, wherein the first electrode strips and the second electrode strips are insulated from and intersected with each other; the scanning device is configured to provide driving signals to the plurality of first electrode strips in turn, the sensing signal providing device is configured to provide sensing signals to the second electrode strips, and a capacitor is formed between each first electrode strip and a second electrode strip adjacent thereto; the plurality of second electrode strips are connected with the identification device, and transmit signals that reflect quantities of the capacitors to the identification device, the identification device is configured to determine a morphology of a fingerprint based on the signals.

CROSS-REFERENCE TO RELATED APPLICATION

This is a National Phase Application filed under 35 U.S.C. 371 as a national stage of PCT/CN2017/094073, filed Jul. 24, 2017 an application claiming the benefit of Chinese Application No. 201610843173.9, filed Sep. 22, 2016, the content of each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to the field of fingerprint identification apparatus, and particularly to a fingerprint identification panel, a display apparatus comprising the fingerprint identification panel and a method for driving the fingerprint identification panel.

BACKGROUND

At present, many electronic apparatuses are provided with a fingerprint identification device so as to enhance security of the electronic apparatus. Common fingerprint identification device is a self-capacitive fingerprint identification device. In particular, the fingerprint identification device comprises a plurality of fingerprint identification electrodes, and each fingerprint identification electrode is connected with a signal lead wire. In a case that a fingerprint covers the fingerprint identification electrode, a capacitor is formed between the fingerprint and the fingerprint identification electrode, and a signal is output to a corresponding signal lead wire. The morphology of the fingerprint can be determined by the signal output from the signal lead wire.

SUMMARY

The present application provides a fingerprint identification panel, a display apparatus and a method for driving the fingerprint identification panel. In the fingerprint identification panel, the number of the electrodes for identifying a fingerprint is large and a space occupied by lead wires is small.

The present application provides a fingerprint identification panel comprising a plurality of first electrode strips, a plurality of second electrode strips, a scanning device, a sensing signal providing device and an identification device, wherein

the plurality of first electrode strips and the plurality of second electrode strips are insulated from and intersected with each other;

the scanning device is configured to provide driving signals to the plurality of first electrode strips in turn, and the sensing signal providing device is configured to provide sensing signals to the plurality of second electrode strips, and a capacitor is formed between each of the plurality of first electrode strips and one second electrode strip adjacent to the first electrode strip;

the plurality of second electrode strips are connected with the identification device, and are configured to transmit signals that reflect electricity quantities of the capacitors to the identification device; and

the identification device is configured to determine a morphology of a fingerprint based on the signals received from the second electrode strips.

Optionally, each of the first electrode strips include a plurality of first sub-electrodes electrically connected in series, each of the second electrode strips include a plurality of second sub-electrodes electrically connected in series, and the fingerprint identification panel further comprises a base substrate, the first sub-electrodes and the second sub-electrodes are provided on the base substrate.

Optionally, both the first sub-electrodes and the second sub-electrodes have a maximum length no larger than 50 μm.

Optionally, both the first sub-electrodes and the second sub-electrodes are made of transparent material.

Optionally, both the first sub-electrodes and the second sub-electrodes are of a diamond shape.

Optionally, the plurality of first electrode strips and the plurality of second electrode strips are provided on different base substrates.

Optionally, the scanning device includes a plurality of cascaded shift registers, each shift register corresponds to one first electrode strip, and the shift register is configured to provide a driving signal to the first electrode strip corresponding to the shift register.

Optionally, the scanning device includes a clock signal line, a trigger signal input terminal and a reset signal input terminal, each shift register includes a clock signal terminal, a signal input terminal, a low level signal terminal, a storage capacitor, a plurality of transistors, a reset terminal and a signal output terminal, and the plurality of transistors include a pull-up transistor, an input transistor, a pull-down transistor and a pull-down control transistor, wherein

the clock signal terminal is connected with the clock signal line;

a first electrode of the input transistor is connected with the signal input terminal, and a gate of the input transistor is connected with the first electrode of the input transistor;

a gate of the pull-up transistor is connected with a second electrode of the input transistor, a first electrode of the pull-up transistor is connected with the clock signal terminal, and a second electrode of the pull-up transistor is connected with the signal output terminal;

a first terminal of the storage capacitor is connected with the gate of the pull-up transistor, and a second terminal of the storage capacitor is connected with the second electrode of the pull-up transistor;

a gate of the pull-down transistor and a gate of the pull-down control transistor are connected and both are connected with the reset terminal of the shift register, a first electrode of the pull-down transistor is connected with the signal output terminal, and a second electrode of the pull-down transistor is connected with the low level signal terminal;

a first electrode of the pull-down control transistor is connected with the second electrode of the input transistor, and a second electrode of the pull-down control transistor is connected with the low level signal terminal;

the signal input terminal of the shift register of a first stage is connected with the trigger signal input terminal, and the signal input terminal of each of the shift registers of the remaining stages is connected with the signal output terminal of the shift register of a previous stage; and

the reset terminal of the shift register of a last stage is connected with the reset signal input terminal, and the reset terminal of each of the shift registers of the remaining stages is connected with the signal output terminal of the shift register of a next stage.

Optionally, the plurality of transistors are N type transistors.

Optionally, the identification device is further configured to determine a position of a finger touching the fingerprint identification panel based on the signals received from the second electrode strips.

As another aspect of the present application, there is further provided a display apparatus, which comprises a fingerprint identification panel and a display panel, wherein the fingerprint identification panel is the above fingerprint identification panel.

Optionally, the display apparatus further comprises a comparison device, wherein a standard fingerprint is stored in advance in the comparison device and the comparison device is configured to judge whether or not a fingerprint identified by the fingerprint identification panel matches with the standard fingerprint.

Optionally, the fingerprint identification panel is configured to identify a fingerprint in real time, and the fingerprint identification panel is further configured to determine a position of a touch point, and the comparison device is configured to generate an instruction for controlling the display apparatus to stop performing a touch operation in case of mismatch between the fingerprint identified by the fingerprint identification panel and the standard fingerprint.

Optionally, in a case that the first sub-electrodes and the second sub-electrodes are made of transparent material, the fingerprint identification panel is provided on a light emergent side of the display panel.

As still another aspect of the present application, there is further provided a method for driving the above fingerprint identification panel to identify a fingerprint, the method comprising:

applying, by the scanning device, driving signals sequentially to the plurality of first electrode strips; and

determining, by the identification device, a morphology of a fingerprint based on signals received from the second electrode strips.

Optionally, the method further comprises:

determining, by the identification device, position coordinates of a touch point based on the signals received from the plurality of second electrode strips.

Reference numerals:110: first sub-electrode120: second sub-electrode200: scanning device210: shift register300: identification device400: sensing signal providing device

DETAILED DESCRIPTION

Embodiments of the present application will be explained in detail below in conjunction with drawings. It should be noted that the embodiments described herein are only used to illustrate and explain the present application, but not to limit the present application.

In an existing fingerprint identification device, since each fingerprint identification electrode is connected with one signal lead wire, in order to increase detection accuracy, it is required to increase amount of the fingerprint identification electrodes and thus the amount of the signal lead wires will be increased accordingly, resulting in a large size of the fingerprint identification device and a large space to be occupied.

Therefore, it is desired to arrange the fingerprint identification electrodes as many as possible without increasing the size of the fingerprint identification device.

As shown inFIG. 1andFIG. 3, a fingerprint identification panel provided in the present application includes a plurality of first electrode strips, a plurality of second electrode strips, a scanning device200, a sensing signal providing device400and an identification device300(seeFIG. 3). As shown inFIG. 1, each of the first electrode strips include a plurality of first sub-electrodes110connected in series, and each of the second electrode strips include a plurality of second sub-electrodes120connected in series.

The plurality of first electrode strips and the plurality of second electrode strips are insulated from and intersected with each other.

The scanning device200is configured to provide driving signals to the plurality of first electrode strips in turn, and the sensing signal providing device400is configured to provide a sensing signal to each second electrode strip.

In a case that one first electrode strip receives the driving signal, a capacitor may be formed between the first electrode strip and an adjacent second electrode strip, as shown inFIG. 2.

As shown inFIG. 3, the plurality of second electrode strips are connected with the identification device300, and the identification device300is configured to determine a morphology of a fingerprint based on signals transmitted to the identification device300by the second electrode strips.

As shown inFIG. 2, in a case that a fingerprint covers above the powered first electrode strip and second electrode strip, the fingerprint, a capacitor C1and a capacitor C2respectively formed between the fingerprint and the first electrode strip and the second electrode strip, a capacitor C3formed between the first electrode strip and the second electrode strip, the first electrode strip and the second electrode strip form a loop, resulting in change in electricity quantity of the capacitor C3.

The fingerprint includes ridges and valleys, since a distance from a ridge to the fingerprint identification panel is different from that from a valley to the fingerprint identification panel, changes in electricity quantity caused by the ridge and the valley are different, and therefore, whether the fingerprint above the first electrode strip and the second electrode strip is a ridge or a valley can be determined based on the changes in electricity quantity of the capacitor C3.

As shown inFIG. 4, the plurality of first electrode strips and the plurality of second electrode strips are intersected with each other, thus the fingerprint identification panel may be divided into multiple cells (each cell is formed as a node). When the surface of the fingerprint identification panel is touched by a finger, a plurality of cells are covered, causing changes in electricity quantities of capacitors formed between first electrode strips and second electrode strips corresponding to the cells. Thus signals transmitted to the identification device300from the second electrode strips may be changed. When the surface of the fingerprint identification panel is touched by the finger, electricity quantities of the capacitors corresponding to a plurality of cells may be changed, and then points at which changes in the electricity quantities of the capacitors are larger than a preset threshold are reported, as effective points, to the identification device300. Coordinates (including a coordinate on an X axis and a coordinate on a Y axis) of a point at a center position of all of the effective points is determined as coordinates of a touch point by the identification device300.

While determining the coordinates of the touch point, the identification device300can determine morphology of the fingerprint according to specific changes in electricity quantities of points at which the changes in electricity quantities exceed the preset threshold. Specifically, change in the electricity quantity of a point corresponding to a valley of the fingerprint is greater than that of a point corresponding to a ridge of the fingerprint, based on which, the identification device300can determine the morphology of the fingerprint, as shown inFIG. 5.

One first electrode strip is connected with one lead wire, that is, the first sub-electrodes in a single first electrode strip are connected with a single lead wire. Similarly, one second electrode strip is connected with the identification device through a single lead wire while being connected with the sensing signal providing device through a single lead wire, that is, the second sub-electrodes in a single second electrode strip are connected with the identification device through a single lead wire, and are connected with the sensing signal providing device through a single lead wire, thereby reducing the number of lead wires, so the space for arranging the first electrode strips and second electrode strips is enlarged, and space for arranging the lead wires is reduced. Compared with the self-capacitive fingerprint identification apparatus in the prior art, in the same space, more first sub-electrodes and second sub-electrodes can be arranged in the fingerprint identification panel provided by the present application, so that the accuracy of fingerprint identification can be improved.

In the implementations ofFIG. 1andFIG. 3, the fingerprint identification panel comprises N first electrode strips, a first first electrode strip is connected with the scanning device200through a lead wire Tx1, a second first electrode strip is connected with the scanning device200through a lead wire Tx2, and so on, an n-th first electrode strip is connected with the scanning device200through a lead wire Txn. The fingerprint identification panel comprises N second electrode strips, a first second electrode strip is connected with the identification device300through a lead wire Rx1, and so on, an n-th second electrode strip is connected with the identification device300through a lead wire Rxn.

In the present application, there is no special limitation to specific structures of the first electrode strips and the second electrode strips.

In the embodiment shown inFIG. 1, each first electrode strip includes a plurality of first sub-electrodes110electrically connected in series, each second electrode strip includes a plurality of second sub-electrodes120electrically connected in series, the fingerprint identification panel also includes a base substrate, the first sub-electrodes and the second sub-electrodes are disposed on the base substrate. In this way, the overall thickness of the fingerprint identification panel can be reduced. Of course, the first sub-electrodes and the second sub-electrodes may also be disposed on different base substrates.

In the embodiment shown inFIG. 3, each first electrode strip is formed by one strip-shaped first sub-electrode, each second electrode strip is formed by one strip-shaped second sub-electrode, and the first electrode strips and the second electrode strips are respectively arranged on two different base substrates, and then the two base substrates are assembled together, so that the first electrode strips and the second electrode strips are intersected with each other.

FIG. 1shows an implementation of the first sub-electrodes110and the second sub-electrodes120. In this implementation, both the first sub-electrodes110and second sub-electrodes120are of a diamond shape. The second sub-electrodes120of a single second electrode strip are directly connected with each other, and the first sub-electrodes110of a single first electrode strip are connected through metal bridges. Alternatively, the first sub-electrodes110of a single first electrode strip are directly connected with each other, and the second sub-electrodes120of a single second electrode strip are connected through metal bridges. In this implementation, the first sub-electrodes110and the second sub-electrodes120can be arranged throughout the whole identification region, thus increasing the number of electrodes, so that the morphology of the fingerprint can be identified more accurately.

In the present application, there is no special restriction to the specific material of the first sub-electrodes110and the second sub-electrodes120.

As an optional implementation, the first sub-electrodes110and the second sub-electrodes120may be made of a transparent electrode material (for example, ITO). In this implementation, the fingerprint identification panel may be provided in a display region of a display panel and stacked on the display panel. Since the first sub-electrodes110and the second sub-electrodes120are made of a transparent electrode material, in a case that the fingerprint identification panel is provided on the light emergent side of the display panel, a normal display of the display panel will not be affected. Because the first sub-electrodes110and the second sub-electrodes120are arranged throughout the fingerprint identification panel, no matter which position of the fingerprint identification panel is touched by a finger, the morphology of the fingerprint can be identified, enlarging the operation area of the fingerprint identification panel.

In order to further improve the accuracy of fingerprint detection, optionally, the first sub-electrodes110and the second sub-electrodes120have a maximum length no larger than 50 μm.

In order to provide driving signals, as shown inFIG. 1, optionally, the scanning device200includes multiple cascaded shift registers210, each shift register210corresponds to one first electrode strip, and the shift register210can provide a driving signal to the first electrode strip corresponding to the shift register210.

As shown inFIG. 1, the scanning device includes a clock signal line, a trigger signal input terminal CP and a reset signal input terminal.FIG. 7shows a shift register with a simple structure, as shown inFIG. 7, the shift register includes a clock signal terminal CLK, a signal input terminal Output[n−1], a low level signal terminal Vss, a storage capacitor C1, a plurality of transistors, a reset terminal and a signal output terminal Output[n], and the plurality of transistors include a pull-up transistor T3, an input transistor T1, a pull-down transistor T4and a pull-down control transistor T2. Here n is the number of stages of the shift registers, and n is a nature number.

A first electrode of the input transistor T1is connected with the signal input terminal Output[n−1], and a gate of the input transistor T1is connected with the first electrode of the input transistor T1.

A gate of the pull-up transistor T3is connected with a second electrode of the input transistor T1, a first electrode of the pull-up transistor T3is connected with the clock signal terminal CLK, and a second electrode of the pull-up transistor T3is connected with the signal output terminal Output[n].

A first terminal of the storage capacitor C1is connected with the gate of the pull-up transistor T3, and a second terminal of the storage capacitor C1is connected with the second electrode of the pull-up transistor T3.

A gate of the pull-down transistor T4and a gate of the pull-down control transistor T2are connected and both are connected with the reset terminal of the shift register, a first electrode of the pull-down transistor T4is connected with the signal output terminal Output[n] and a second electrode of the pull-down transistor T4is connected with the low level signal terminal Vss.

A first electrode of the pull-down control transistor T2is connected with the second electrode of the input transistor T1, and a second electrode of the pull-down control transistor T2is connected with the low level signal terminal Vss.

The signal input terminal Output[0] of the shift register of the first stage is connected with the trigger signal input terminal CP, and the signal input terminal of each of the shift registers of the remaining stages is connected with the signal output terminal of the shift register of a previous stage.

The reset terminal of the shift register of the last stage is connected with the reset signal input terminal, and the reset terminal of each of the shift registers of the remaining stages is connected with the signal output terminal Output[n+1] of the shift register of a next stage.

An operation period of the shift register includes a charging stage, an output stage and a pull-down stage.FIG. 6shows a timing chart of signals at respective stages.

In the charging stage, the input signal is at a high level, the input transistor T1is turned on so as to charge the first capacitor C1, in this stage, the pull-up transistor T3is turned on, a signal input through the clock signal input terminal CLK is at a low level, and therefore, the pull-up transistor T3outputs a low-level signal to the signal output terminal.

In the pull-up stage, the input signal is at a low level, the input transistor T1is turned off, and the pull-up transistor T3is turned on due to the bootstrap of the first capacitor C1. At this time, an input signal of the clock signal terminal CLK is at a high level, so the pull-up transistor T3outputs a high-level signal to the signal output terminal.

In the pull-down stage, the pull-down control transistor T2and the pull-down transistor T4are turned on, so that a level at the output terminal of the shift register can be pulled down.

It can be seen that the signal received by the first electrode strip is actually a clock signal provided by the clock signal line. The trigger signal input by the trigger signal input terminal CP is a field synchronization signal, which is initially at a high level, of the first electrode strip. At the time when a first rising edge of the clock signal arrives, a first first electrode strip is charged, and in the meanwhile the trigger signal becomes at a low level. Then at the time when a second rising edge of the clock signal arrives, a second first electrode strip is charged, and so on. At each rising edge of the clock signal, one of the first electrode strips is charged. When a finger contacts a position of the fingerprint identification panel, change in a capacitance at the position occurs. The second electrode strips detect the change and transmit it, as a signal, to the identification device. After signals of all nodes are processed, the morphology of the fingerprint can be obtained.

Optionally, the identification device can also determine the position at which the finger touches the fingerprint identification panel according to the signals transmitted by the second electrode strips. In this implementation, the fingerprint recognition panel has both functions of fingerprint identification and touch control.

The coordinates of the touch point are composed of the row number of the first electrode strip receiving a driving signal (that is, coordinate on the Y axis inFIG. 4) and the column number of the second electrode strip at which the signal changes (that is, coordinate on the X axis inFIG. 4).

In order to determine the row number of the first electrode strip that is receiving the driving signal, optionally, a counter may be provided in the fingerprint identification panel. The count value obtained by the counter is the number of the clock signal plus 1. An initial number of the clock signal is 0 and the count value is 1, which indicates that the first first electrode strip is receiving a scanning signal, and so no. The coordinates of the touch point can be determined according to the row number of the first electrode strip that is receiving the scanning signal and the column number of the second electrode strip at which the signal is changed.

When the count value obtained by the counter is n, the clock number is cleaned up when the next count begins.

In the fingerprint identification panel of the present application, one first electrode strip is connected with a single lead wire, one second electrode strip is connected with the identification device through a single lead wire while being connected with the sensing signal providing device through a single lead wire, thereby the space for arranging the first electrode strips and second electrode strips is enlarged, and space for arranging the lead wires is reduced. Compared with the self-capacitive fingerprint identification apparatus in the prior art, in the same space, more first sub-electrodes and second sub-electrodes can be arranged in the fingerprint identification panel provided by the present application, so that the accuracy of fingerprint identification can be improved.

As another aspect of the present application, there is also provided a display apparatus comprising a fingerprint identification panel and a display panel, wherein the fingerprint identification panel is the above fingerprint identification panel.

It could be easily understood that the fingerprint identification panel should not affect the normal display of the display apparatus.

Optionally, the display apparatus includes a comparison device, wherein a standard fingerprint is stored in the comparison device in advance, and the comparison device can determine whether or not a fingerprint identified by the fingerprint identification panel matches with the standard fingerprint.

In the present application, the fingerprint identification device can be configured to identify whether an acquired fingerprint is a pre-stored fingerprint, thus improving the operation security of the display apparatus.

Optionally, the fingerprint identification panel can identify a fingerprint in real time, and the comparison device can generate a command for controlling the display apparatus to stop performing a touch operation in case of mismatch between the fingerprint identified by the fingerprint identification panel and the fingerprint pre-stored in the display apparatus.

In a case that the first sub-electrodes and the second sub-electrodes are made of a transparent material, the fingerprint identification panel can be provided on a light emergent surface of a display region of the display panel, that is, the fingerprint identification panel is of an on-cell type. In this implementation, the display panel and the fingerprint identification panel can be independently driven so that the structure of each drive circuit can be simplified.

As another aspect of the present application, there is further provided a method for driving the fingerprint identification panel, the method comprising:

applying, by the scanning device, driving signals sequentially to the plurality of first electrode strips; and

determining, by the identification device, a morphology of a finger based on signals received from the plurality of second electrode strips.

As described above, the fingerprint identification panel also has a function of determining the coordinates of a touch point, and therefore, the driving method further includes:

determining, by the identification device, position coordinates of a touch point based on the signals received from the plurality of second electrode strips.

It should be understood that, the foregoing embodiments are only exemplary embodiments used for explaining the principle of the present invention, but the present invention is not limited thereto. Various variations and improvements may be made by a person skilled in the art without departing from the spirit and essence of the present invention, and these variations and improvements also fall into the protection scope of the present invention.