CN114299557A - A fingerprint identification panel, a control method thereof, and a display device - Google Patents

Abstract

The invention provides a fingerprint identification panel, a control method thereof, and a display device, which relate to the field of display technology. The fingerprint identification panel includes a fingerprint identification substrate and a light adjustment substrate; the light adjustment substrate includes a first substrate, a second substrate and a liquid crystal layer; the first substrate includes a first substrate and a first electrode, and the first electrode is arranged on the first substrate and the liquid crystal layer, the second substrate includes a second substrate and a second electrode, the second electrode is disposed between the second substrate and the liquid crystal layer, and at least one of the first electrode and the second electrode includes a plurality of Discrete sub-electrodes; the liquid crystal layer is configured to: in the fingerprint identification state, the light beams directed towards the fingerprint identification substrate can be collected.

Description

A fingerprint identification panel, control method thereof, and display device

technical field

The present invention relates to the field of display technology, in particular to a fingerprint identification panel, a control method thereof, and a display device.

Background technique

With the development of technology, under-screen fingerprint recognition technology is applied to various display devices. The current off-screen fingerprint recognition technology includes off-screen optical fingerprint recognition technology, and the current optical fingerprint recognition technology often has problems such as serious crosstalk from large angles of light, high cost, and inability to achieve large size.

Therefore, there is an urgent need for an under-screen optical fingerprint recognition technology to solve the above problems.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a fingerprint identification panel, a control method thereof, and a display device, which can realize fingerprint identification, effectively reduce large-angle crosstalk of light, and facilitate the preparation of large-sized display devices.

To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

In one aspect, a fingerprint identification panel is provided, the fingerprint identification panel is applied to a display device, the display device includes a display panel; the fingerprint identification panel is located on a side of the display panel away from a display side;

The fingerprint identification panel includes a fingerprint identification substrate and a light adjustment substrate, the light adjustment substrate is arranged between the fingerprint identification substrate and the display panel; the light adjustment substrate includes a first substrate, a second substrate and a liquid crystal layer , the liquid crystal layer is arranged between the first substrate and the second substrate; the light emitted by the display panel passes through the first substrate and the liquid crystal layer in turn after being reflected by the finger in the fingerprint recognition state , and shoot at the second substrate and the fingerprint identification substrate in sequence;

The first substrate includes a first substrate and a first electrode, the first electrode is disposed between the first substrate and the liquid crystal layer, and the second substrate includes a second substrate and a second electrode , the second electrode is disposed between the second substrate and the liquid crystal layer, and at least one of the first electrode and the second electrode includes a plurality of discrete sub-electrodes;

The liquid crystal layer is configured to be capable of condensing light directed toward the fingerprint recognition substrate in the fingerprint recognition state.

Optionally, the first electrode includes a plurality of discrete sub-electrodes; and the second electrode is provided in a whole layer.

Optionally, the first substrate further includes a first alignment film disposed between the first electrode and the liquid crystal layer; the second substrate further includes a first alignment film disposed between the second electrode and the liquid crystal layer the second alignment film between;

The first alignment film and the second alignment film are configured to: under the condition that the first electrode and the second electrode do not generate an electric field, work together so that the liquid crystal layer is not in a non-fingerprint identification state. Converging the light rays directed to the fingerprint identification substrate;

The first electrode and the second electrode are configured to generate an electric field, so that the liquid crystal layer condenses the light emitted to the fingerprint identification substrate in the fingerprint identification state.

Optionally, the second substrate further includes a filter layer disposed between the second substrate and the second alignment film.

Optionally, the fingerprint recognition substrate includes a third substrate and a first flat layer, a fingerprint recognition unit, a second flat layer and a passivation layer that are sequentially stacked on the third substrate;

The fingerprint identification unit includes a third electrode, a photodiode and a fourth electrode sequentially stacked on the first flat layer, the photodiode is configured to receive the liquid crystal received by the liquid crystal in the fingerprint identification state The layers converge the light and generate the fingerprint signal.

Optionally, the fingerprint identification substrate further includes a control unit, and the control unit is configured to: control the opening or closing of the photodiode;

The fingerprint identification substrate further includes a first thin film transistor and a second thin film transistor arranged in the same layer, and the first thin film transistor is arranged between the third substrate and the first flat layer;

Each of the first thin film transistor and the second thin film transistor includes an active layer, a gate electrode, a source electrode and a drain electrode, respectively;

Wherein, the first electrode of the dimming substrate is electrically connected to the drain of the first thin film transistor through the passivation layer and the via hole on the second flat layer in sequence; The via hole on the first flat layer is electrically connected to the drain of the second thin film transistor, and the photodiode is electrically connected to the control unit.

Optionally, the second substrate further includes a black matrix disposed between the second substrate and the second electrode, and the orthographic projection of the black matrix on the fingerprint recognition substrate is the same as the photodiode. The orthographic projections on the fingerprint recognition substrate do not overlap or partially overlap.

In another aspect, a display device is provided, comprising a display panel and the above-mentioned fingerprint identification panel;

The fingerprint recognition panel is located on a side of the display panel away from the display side.

Optionally, the display device further includes a driving module, the driving module is electrically connected to the first electrode and the second electrode, respectively; the driving module is configured to connect to the first electrode and the second electrode. The two electrodes provide a control voltage, so that the liquid crystal layer of the fingerprint identification panel can condense the light emitted to the fingerprint identification substrate in the fingerprint identification state.

In yet another aspect, a method for controlling the above fingerprint identification panel is provided, wherein the fingerprint identification panel includes a control unit;

The control method includes:

the control unit inputs an opening signal to the fingerprint identification substrate of the fingerprint identification panel;

The fingerprint identification substrate receives the light reflected by the finger collected by the light adjustment substrate of the fingerprint identification panel, and generates a fingerprint signal.

An embodiment of the present invention provides a fingerprint identification panel, the fingerprint identification panel is applied to a display device, and the display device includes a display panel; the fingerprint identification panel is located on a side of the display panel away from the display side; the fingerprint identification panel includes a fingerprint identification substrate and The dimming substrate is arranged between the fingerprint identification substrate and the display panel; the dimming substrate includes a first substrate, a second substrate and a liquid crystal layer, and the liquid crystal layer is arranged between the first substrate and the second substrate; the display panel emits After the light reflected by the finger in the fingerprint recognition state, it passes through the first substrate and the liquid crystal layer in turn, and then goes to the second substrate and the fingerprint recognition substrate in turn; the first substrate includes a first substrate and a first electrode, and the first electrode is arranged on the Between the first substrate and the liquid crystal layer, the second substrate includes a second substrate and a second electrode, the second electrode is disposed between the second substrate and the liquid crystal layer, and at least one of the first electrode and the second electrode One includes a plurality of discrete sub-electrodes; the liquid crystal layer is configured to: in the fingerprint identification state, the light beams directed towards the fingerprint identification substrate can be collected. Therefore, while realizing fingerprint identification, the problem of large-angle crosstalk of light can also be effectively reduced, the signal-to-noise ratio can be improved, and the preparation of a large-size display device can be facilitated, thereby reducing the cost.

The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the description, and in order to make the above-mentioned and other purposes, features and advantages of the present application more obvious and easy to understand , and the specific embodiments of the present application are listed below.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of an optical fingerprint identification device in a related art provided by an embodiment of the present invention;

2 is a schematic structural diagram of a light-converging device in a related art according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a display device according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of another display device according to an embodiment of the present invention;

5 is a schematic diagram of a liquid crystal phase retardation of a light-adjusting substrate under different electric fields according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a fingerprint identification substrate according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the embodiments of the present invention, words such as "first", "second", "third" and "fourth" are used to distinguish the same or similar items with basically the same function and function, which is only for the purpose of clearly describing the present invention. The technical solutions of the invention embodiments should not be understood as indicating or implying relative importance or implying the quantity of the indicated technical features.

In the embodiments of the present invention, "a plurality" means two or more, and "at least one" means one or more, unless otherwise expressly and specifically defined.

In the embodiments of the present invention, the orientations or positional relationships indicated by the terms "upper", "lower", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or It is implied that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

The current mainstream under-screen fingerprint recognition technology includes optical fingerprint recognition technology. In the optical fingerprint identification device of the related art, the structure for converging the light reflected by the user's finger often includes a microlens, a collimating diaphragm, and a silicon-based substrate made by a CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) process. one or more of etc. FIG. 1 shows an optical fingerprint identification device in the related art. Referring to FIG. 1 , the optical fingerprint identification device includes a silicon-based substrate 51 made by a CMOS process and a micro-lens 52 formed on the silicon-based substrate 51 . The display device includes a glass substrate 54, an orientation layer 55, a back plate 56, a color light-emitting layer 57, a first encapsulation layer 58, a touch function layer 59, a polarizer 60 and a cover plate 61, which are stacked in sequence. The light G1 emitted by the colored light-emitting layer 57 is reflected by the finger 3 and then directed to the microlens 52 , and the microlens 52 converges the light.

FIG. 2 shows a structure that can replace the silicon-based substrate 51 and the microlens 52 in FIG. 1 . Referring to FIG. 2 , a metal grating 71 , an infrared cut-off layer 72 , a black resin matrix 73 , an optical layer 74 and a microlens 52 are sequentially formed on the silicon base substrate 51 , and the light G3 reflected by the finger passes through the microlens 52 and converges into light. G4, the light G4 is converged by the metal grating 71 again. In this structure, the light G5 is the light directed to other fingerprint identification devices, that is, the light of crosstalk.

When one or more of the structures of microlenses, collimating diaphragms, and silicon-based substrates made by CMOS technology used in the above-mentioned related technologies converge light, for example, a single-layer collimating diaphragm is used, in a strong light environment. The problem of large-angle crosstalk of light is more serious, resulting in a reduction of the signal-to-noise ratio; although the use of multi-layer collimating apertures can reduce the problem of large-angle crosstalk of light, it will also reduce the amount of signal; for example, microlenses and silicon-based CMOS processes The cost is high and the large size cannot be achieved. Therefore, none of the structures for converging light in the above-mentioned related art can well meet the needs of users.

Based on the above, an embodiment of the present invention provides a fingerprint identification panel. Referring to FIG. 3 and FIG. 4 , the fingerprint identification panel 1 is applied to a display device, and the display device includes a display panel 2 ; The side away from the display side; the fingerprint identification panel 1 includes a fingerprint identification substrate 11 and a light adjustment substrate 12, and the light adjustment substrate 12 is arranged between the fingerprint identification substrate 11 and the display panel 2; the light adjustment substrate 12 includes a first substrate 121, a second Two substrates 122 and a liquid crystal layer 123, the liquid crystal layer 123 is disposed between the first substrate 121 and the second substrate 122; the light emitted by the display panel 2 is reflected by the finger 3 in the fingerprint recognition state, and then passes through the first substrate 121 and the liquid crystal in turn. The layer 123 is directed to the second substrate 122 and the fingerprint recognition substrate 11 in sequence.

3 and 4, the first substrate 121 includes a first substrate 1211 and a first electrode 1212, the first electrode 1212 is disposed between the first substrate 1211 and the liquid crystal layer 123, and the second substrate 122 includes a second a substrate 1225 and a second electrode 1222, the second electrode 1222 is disposed between the second substrate 1225 and the liquid crystal layer 123, and at least one of the first electrode 1212 and the second electrode 1222 includes a plurality of discrete sub-electrodes; The liquid crystal layer 123 is configured so as to be able to condense the light incident on the fingerprint recognition substrate 11 in the fingerprint recognition state.

The type and structure of the above-mentioned fingerprint identification panel are not specifically limited here. For example, the above-mentioned fingerprint identification panel may be an optical fingerprint identification panel, an ultrasonic fingerprint identification panel, or the like. FIG. 3 and FIG. 4 both illustrate that the above-mentioned fingerprint identification panel is an optical fingerprint identification panel as an example. Referring to FIG. 3 and FIG. 4 , the above-mentioned fingerprint identification panel includes a fingerprint identification substrate 11 and a light adjustment substrate 12 , and the fingerprint identification substrate 11 includes an optical fingerprint identification substrate.

The above-mentioned display device includes a display panel, and the display panel may include a liquid crystal display panel, or may include an OLED (Organic Light-Emitting Diode, organic light-emitting diode) display panel, which is not specifically limited here.

The above-mentioned fingerprint recognition panel is located on the side of the display panel away from the display side, and the above-mentioned display side refers to the side where the display panel displays, that is, the user presses the side of the display panel with the user's finger in the state of fingerprint recognition, as shown in Figure 3 and the finger 3 shown in FIG. 4 presses one side of the display panel 2 . In this way, the light emitted by the display panel is reflected by the finger in the fingerprint recognition state, and then passes through the first substrate and the liquid crystal layer in turn, and then radiates to the second substrate and the fingerprint recognition substrate in turn. Under the action of the electric field, the liquid crystal layer finally emits the collected light to the fingerprint identification substrate, and fingerprint identification is realized at this time; the liquid crystal layer does not condense the light directed to the fingerprint identification substrate under the action of the electric field, and the fingerprint identification is not performed at this time.

The type and structure of the above-mentioned fingerprint identification substrate are not specifically limited here. For example, the above-mentioned fingerprint identification substrate may be an optical fingerprint identification substrate, an ultrasonic fingerprint identification substrate, or the like. FIG. 3 and FIG. 4 both illustrate that the above-mentioned fingerprint recognition substrate 11 is an optical fingerprint recognition substrate as an example. Referring to FIGS. 3 and 4 , the fingerprint recognition substrate 11 includes a third substrate 111 and a first thin film transistor 41 , a second thin film transistor 42 , a first flat layer 112 , a first thin film transistor 41 , a second thin film transistor 42 , a first flat layer 112 , and a The photodiode 115 , the second planarization layer 113 and the passivation layer 114 , wherein the photodiode 115 is electrically connected to the second transistor 42 through the first metal electrode 116 in the via hole on the first planarization layer 112 .

The specific materials of the first substrate and the second substrate are not limited here. For example, the materials of the first substrate and the second substrate may include glass and PI (polyimide).

The polarity of the liquid crystal in the above-mentioned liquid crystal layer is not specifically limited here. For example, the liquid crystal layer may include positive liquid crystal or negative liquid crystal.

The specific materials of the first electrode and the second electrode are not limited here. For example, the material of the first electrode and the second electrode may include ITO (Indium Tin Oxides, indium tin oxide).

The fact that at least one of the first electrode and the second electrode includes a plurality of discrete sub-electrodes means: the first electrode includes a plurality of discrete sub-electrodes, and the second electrode is arranged in an entire layer; or, the first electrode is an entire layer and the second electrode includes a plurality of discrete sub-electrodes; or, both the first electrode and the second electrode include a plurality of discrete sub-electrodes, which are not specifically limited here. FIGS. 3 and 4 both illustrate that the first electrode 1212 includes three discrete sub-electrodes, and the first electrode 1222 is disposed in a whole layer as an example.

The above-mentioned liquid crystal layer is configured so as to be capable of condensing the light emitted to the fingerprint recognition substrate in the fingerprint recognition state. 3 and 4, the liquid crystal layer forms the convex lens shown in FIG. 3 and FIG. 4 in the fingerprint identification state, so as to condense the light emitted to the fingerprint identification substrate. Specifically, as shown in FIG. 3 , when the first electrode includes three discrete sub-electrodes and the second electrode is disposed in a whole layer, different voltages can be applied to the three discrete sub-electrodes respectively, and the second electrode can be applied to the second electrode. A voltage is applied to make the electric field formed between each sub-electrode and the second electrode different, so that the liquid crystal layer forms a convex lens, and the convex lens can condense the light emitted to the fingerprint identification substrate.

The specific preparation process for the above-mentioned fingerprint identification panel and display panel to form the display device is not limited here. For example, the fingerprint identification panel and the display panel may be prepared respectively, and then the prepared fingerprint identification panel and the display panel are laminated to form For the display device shown in FIG. 3 , referring to FIG. 3 , the second substrate 1225 of the dimming substrate 12 in the fingerprint recognition panel 1 is bonded to the substrate 21 of the display panel 2 to obtain the display device. Including other structures 22 prepared on the substrate 21; or, the substrate of any one of the light-adjustable substrates can also be used as the substrate of the display panel, and the substrate and the display panel are prepared at the same time, and another one of the light-adjustable substrates can be prepared. A substrate and a fingerprint recognition substrate are placed opposite to each other by dripping liquid crystal to form a display device as shown in FIG. 4 . Referring to FIG. Then, the first substrate 1211 and the fingerprint recognition substrate 11 in the dimming substrate 12 are prepared, and the two are placed opposite to each other to form a display device by dripping liquid crystal; alternatively, the dimming substrate in the fingerprint recognition panel can also be prepared first. , and attach the display panel on the dimming substrate, and then attach the dimming substrate attached with the display panel to the fingerprint identification substrate, which is subject to the actual application.

The fingerprint identification panel provided by the embodiment of the present invention includes a fingerprint identification substrate and a light adjustment substrate, and the light adjustment substrate is arranged between the fingerprint identification substrate and the display panel; the light adjustment substrate includes a first substrate, a second substrate and a liquid crystal layer, and the liquid crystal layer is arranged between the first substrate and the second substrate; after the light emitted by the display panel is reflected by the finger in the fingerprint recognition state, it passes through the first substrate and the liquid crystal layer in turn, and then goes to the second substrate and the fingerprint recognition substrate in turn; the first substrate includes The first substrate and the first electrode, the first electrode is arranged between the first substrate and the liquid crystal layer, the second substrate includes the second substrate and the second electrode, and the second electrode is arranged between the second substrate and the liquid crystal layer. Meanwhile, at least one of the first electrode and the second electrode includes a plurality of discrete sub-electrodes; the liquid crystal layer is configured to: in the fingerprint identification state, the light rays directed towards the fingerprint identification substrate can be collected. Since at least one of the first electrode and the second electrode includes a plurality of discrete sub-electrodes, in the fingerprint recognition state, a non-uniform electric field can be generated between the first electrode and the second electrode to control the orientation of the liquid crystal molecules, An electrically variable gradient refractive index distribution is formed, and then a convex lens as shown in Figures 3 and 4 is formed. The convex lens can achieve the effect of focusing and converge the light directed to the fingerprint identification substrate, so that fingerprint identification can be achieved at the same time. , it can also effectively reduce the large-angle crosstalk problem of light, improve the signal-to-noise ratio, and facilitate the preparation of large-size display devices, thereby reducing costs.

In order to facilitate the fabrication of the second electrode, optionally, as shown in FIG. 3 and FIG. 4 , the first electrode 1212 includes a plurality of discrete sub-electrodes; the second electrode 1222 is provided in a whole layer.

The above-mentioned first electrode includes a plurality of discrete sub-electrodes, and the number, width, and spacing of the plurality of discrete sub-electrodes are not specifically limited here. For example, the first electrode may include three, four, five, etc. Sub-electrodes with the same spacing and the same width; alternatively, the first electrode may include three, four, five sub-electrodes with different intervals but the same width; alternatively, the first electrode may include three, four, five, etc. Sub-electrodes with the same pitch but different widths. FIG. 3 and FIG. 4 illustrate that the first electrode 1212 includes three sub-electrodes with the same spacing and the same width as an example.

The specific materials of the above-mentioned first electrodes and second electrodes are not limited here. For example, the materials of the first electrodes and the second electrodes include metal materials.

Optionally, as shown in FIGS. 3 and 4 , the first substrate 121 further includes a first alignment film 1213 disposed between the first electrode 1212 and the liquid crystal layer 123 ; the second substrate 122 further includes a first alignment film 1222 disposed between the first electrode 1212 and the liquid crystal layer 123 . and the second alignment film 1221 between the liquid crystal layer 123 .

Referring to FIG. 3 and FIG. 4 , the first alignment film 1213 and the second alignment film 1221 are configured to: in the case where the first electrode 1212 and the second electrode 1222 do not generate an electric field, the joint action makes the liquid crystal layer 123 in the non-fingerprint The first electrode 1212 and the second electrode 1222 are configured to generate an electric field and make the liquid crystal layer 123 converge the light directed to the fingerprint identification substrate 11 in the fingerprint recognition state. In this way, in the presence of the first alignment film and the second alignment film, whether to apply a voltage to the first electrode and the second electrode, the light-adjustable substrate can be switched between a fingerprint recognition state and a non-fingerprint recognition state.

The materials of the first alignment film and the second alignment film are not specifically limited here. For example, the materials of the first alignment film and the second alignment film may both include PI (Polyimide, polyimide).

其中，λ表示液晶厚度，

表示观测角度。就使得不同位置的液晶可以起到透镜的作用，达到聚焦的效果。图5为平行于第一衬底的方向的宽度为3mm的调光基板在六种不同电压下的相位延迟量，其中横坐标代表调光基板在平行于第一衬底的方向的宽度，单位是mm，纵坐标代表相位延迟量。3 and 4, the liquid crystal in the liquid crystal layer 123 rotates under the action of the electric field, and the deflection angle of the liquid crystal depends on the electric field between each sub-electrode and the second electrode. When different electric fields are applied, the phase retardation of the liquid crystal at different positions is different. The phase retardation is the amount of phase retardation caused by the deflection of the phase of light when passing through the liquid crystal. The calculation formula of the phase retardation is:

where λ is the thickness of the liquid crystal,

Indicates the viewing angle. This enables the liquid crystals at different positions to function as lenses to achieve the effect of focusing. Figure 5 shows the phase retardation of a light-adjustable substrate with a width of 3 mm in the direction parallel to the first substrate under six different voltages, wherein the abscissa represents the width of the light-adjustable substrate in the direction parallel to the first substrate, in units of is mm, and the ordinate represents the amount of phase delay.

Since the deflection angle of the liquid crystal depends on the electric field between each sub-electrode and the second electrode, adjusting the voltage applied to each sub-electrode can change the equivalent radius of curvature of the lens formed by the liquid crystal to achieve the effect of adjusting the focal length.

Optionally, as shown in FIG. 3 and FIG. 4 , the second substrate 122 further includes a filter layer 1223 disposed between the second substrate 1225 and the second alignment film 1221 . Since the strong ambient light above 600nm will pass through the finger, the signal at the edge of the finger will be saturated, and the accuracy of fingerprint recognition will be reduced. Therefore, a filter layer is set in the second substrate to filter out the ambient light above 600nm, reduce optical noise, and improve Signal-to-noise ratio.

The specific material of the above-mentioned filter layer is not limited here. For example, the material of the filter layer may include an infrared cut-off material.

The specific position of the above-mentioned filter layer is not limited here. For example, the filter layer may be disposed between the second substrate and the second electrode; or, the filter layer may be disposed between the second electrode and the second alignment film. between. FIG. 3 and FIG. 4 illustrate the area between the filter layer 1223 and the second substrate 1225 and the second electrode 1222 as an example.

Optionally, as shown in FIG. 3 and FIG. 4 , the fingerprint recognition substrate 11 includes a third substrate 111 , a first flat layer 112 , a fingerprint recognition unit 115 , a second flat layer 112 , a fingerprint recognition unit 115 , and a second flat layer 112 , which are sequentially stacked on the third substrate 111 . layer 113 and passivation layer 114 .

The fingerprint identification unit includes a third electrode, a photodiode and a fourth electrode that are sequentially stacked on the first flat layer, and the photodiode is configured to receive the light collected by the liquid crystal layer in the fingerprint identification state, and Generate a fingerprint signal. Thus, the light collected by the light-adjustable substrate is received by the photodiode, and fingerprint recognition is realized.

The specific material of the third substrate is not limited here. For example, the material of the third substrate may include glass and PI (polyimide).

The specific materials of the first flat layer and the second flat layer are not limited here. For example, the materials of the first flat layer and the second flat layer may include organic materials.

The specific material of the above-mentioned passivation layer is not limited here. For example, the material of the passivation layer may include inorganic materials.

The specific shapes of the first electrode and the second electrode are not limited here. Exemplarily, the cross-sectional shape of the first electrode and the second electrode along a direction perpendicular to the third substrate may be a rectangle, a trapezoid, or the like.

There is no specific limitation on the types of the above photodiodes, for example, the photodiodes may include PIN photodiodes. The photodiode and the electrodes on the upper and lower sides of the photodiode are arranged vertically, and the first doped part, the intrinsic part, and the second doped part in the photodiode are arranged vertically in sequence, and the vertical direction here is the same as that of the third lining The bottom is vertical; or, the photodiode and the electrodes on the left and right sides of the photodiode are arranged laterally, and the first doped part, the intrinsic part, and the second doped part in the photodiode are arranged laterally in sequence, and the lateral direction here is the same as that of the third substrate. Bottom parallel.

Optionally, the fingerprint identification substrate further includes a control unit, and the control unit is configured to: control the opening or closing of the photodiode; with reference to FIG. 3 and FIG. 4 , the fingerprint identification substrate 11 further includes a first thin film transistor 41 arranged in the same layer. And the second thin film transistor 42 , the first thin film transistor 41 is disposed between the third substrate 111 and the first planarization layer 112 .

The first thin film transistor and the second thin film transistor respectively include an active layer, a gate electrode, a source electrode and a drain electrode; wherein, the first electrode of the dimming substrate passes through the passivation layer and the via hole on the second flat layer and the first electrode in turn. The drain of a thin film transistor is electrically connected; the photodiode is electrically connected to the drain of the second thin film transistor through the via hole on the first flat layer, and the photodiode is electrically connected to the control unit.

The arrangement of the first thin film transistor and the second thin film transistor in the same layer means that the active part of the first thin film transistor and the active part of the second thin film transistor are arranged in the same layer, the gate of the first thin film transistor and the gate of the second thin film transistor The electrodes are arranged in the same layer, and the source and drain electrodes of the first thin film transistor and the source and drain electrodes of the second thin film transistor are arranged in the same layer. Wherein, the same-layer setting refers to the one-time patterning process.

According to the positional relationship of the electrodes, the above-mentioned first thin film transistor and second thin film transistor can be divided into two types: one is that the gate is located under the source and the drain, and this type is called a bottom-gate thin film transistor; The gate is located above the source and drain, and this type is called a top-gate thin film transistor.

The above control unit can input a bias voltage signal to the photodiode, and the photodiode is turned on or off under the control of the bias voltage signal. The first electrode is electrically connected to the drain of the first thin film transistor, and the electrical signal formed by the photodiode can be output through the first thin film transistor. The control method is simple and easy to implement.

The material for the electrical connection between the first electrode of the above-mentioned dimming substrate and the drain of the first thin film transistor through the passivation layer and the via hole on the second flat layer is not limited here. For example, refer to FIG. 3 and FIG. 4 As shown, the first electrode of the dimming substrate can pass through the fourth metal electrode 119 arranged in the via hole of the first flat layer 112 and the third metal electrode 118 arranged in the via hole of the second flat layer 113 and the connection between the first thin film transistor and the first thin film transistor. Drain is electrically connected.

The material for electrically connecting the photodiode to the drain of the second thin film transistor through the via hole on the first flat layer is not limited here. For example, as shown in FIG. 3 and FIG. 4 , the photodiode 115 is provided on the first The first metal electrode 116 in the via hole of the flat layer 112 is electrically connected to the drain of the second thin film transistor. It should be noted that, in order to make the film layer more flat, as shown in FIGS. 3 and 4 , via holes are also provided above the second flat layer 113 corresponding to the photodiodes 115 , and the second metal electrodes 117 are filled in the via holes.

The photodiode and its related specific structure will now be described with reference to FIG. 6 . Referring to FIG. 6 , a buffer layer 81 , an active layer 421 of the second transistor 42 , a gate insulating layer 82 , a gate 422 of the second transistor 42 , an interlayer dielectric layer 83 , The source electrode 423 and the drain electrode 424 of the second transistor 42 (the source electrode 423 and the drain electrode 424 are respectively electrically connected to the active layer 421 through the interlayer dielectric layer 83 and the via hole on the gate insulating layer 82 in sequence), the first protection layer 84, the first flat layer 112, the second protective layer 85, the first connection electrode 86 (the first connection electrode 86 passes through the second protective layer 85, the first flat layer 112, the via holes on the first protective layer 84 and the Drain 424 is electrically connected), fingerprint identification unit 115 (photodiode 115 includes first electrode 1151, photodiode 1152 and second electrode 1153), protective electrode 87, cover layer 88, second flat layer 113, third protective layer 89 , a second connection electrode 90 (the second connection electrode 90 is electrically connected to the protection electrode 87 through the third protection layer 89 and the via hole on the second flat layer 113 in sequence) and the passivation layer 114 .

Optionally, as shown in FIG. 3 and FIG. 4 , the second substrate 122 further includes a black matrix 1224 disposed between the second substrate 1225 and the second electrode 1222 , and the orthographic projection of the black matrix 1224 on the fingerprint identification substrate 11 It does not overlap or partially overlaps with the orthographic projection of the photodiode 115 on the fingerprint recognition substrate 11 . Therefore, the black matrix can block the external light emitted to the first thin film transistor to ensure the performance of the first thin film transistor, and the light reflected by the finger can be directed to the photodiode from the gap of the black matrix, thereby performing fingerprint identification.

The specific material of the black matrix is not limited here. For example, the material of the black matrix includes black resin.

The specific position of the black matrix is not limited here. For example, the black matrix may be arranged between the second substrate and the filter layer; or, the black matrix may be arranged between the filter layer and the second electrode. FIG. 3 and FIG. 4 both illustrate that the black matrix 1224 is disposed between the second substrate 1225 and the filter layer 1223 as an example.

An embodiment of the present invention further provides a display device, including a display panel and the above-mentioned fingerprint identification panel; the fingerprint identification panel is located on a side of the display panel away from the display side.

The above-mentioned display device may be a flexible display device (also known as a flexible screen) or a rigid display device (ie, a display screen that cannot be bent), which is not limited here. The above-mentioned display device may be an OLED (Organic Light-Emitting Diode, organic light-emitting diode) display device, and may also be an LCD (Liquid Crystal Display, liquid crystal display device) display device.

The above-mentioned display device can be any product or component with a display function, such as a TV, a digital camera, a mobile phone, a tablet computer, etc. The above-mentioned display device can also be applied to fields such as identification, medical equipment, etc. The products that have been promoted or have good promotion prospects include Security identity authentication, smart door locks, medical image collection, etc. The display device has the advantages of good fingerprint recognition effect, good display effect, long life, high stability, high contrast, good imaging quality and high product quality.

Optionally, the display device further includes a driving module, which is electrically connected to the first electrode and the second electrode respectively; the driving module is configured to provide a control voltage to the first electrode and the second electrode, so that the liquid crystal layer of the fingerprint identification panel is In the fingerprint identification state, the light beams directed to the fingerprint identification substrate can be collected. 3 and FIG. 4 , the dimming substrate 12 forms a convex lens to condense the light emitted to the fingerprint identification substrate 11 , so that the fingerprint identification substrate 11 can better perform fingerprint identification.

Optionally, the control module is arranged on the display panel or the fingerprint identification panel.

The position of the control module on the display panel or the fingerprint recognition is not specifically limited here. For example, the display panel may include an FPC (Flexible Printed Circuit, flexible circuit board), and the control module may be integrated on the FPC. Alternatively, the control module may be disposed on the first substrate or the second substrate for fingerprint identification.

An embodiment of the present invention further provides a control method for the above fingerprint identification panel, where the fingerprint identification panel includes a control unit.

The control method includes:

S01. The control unit inputs an opening signal to the fingerprint identification substrate of the fingerprint identification panel.

The above-mentioned control unit may be a chip such as a single-chip microcomputer, an ARM (Advanced RISC Machines, an advanced reduced instruction set computing machine) or an FPGA (Field Programmable Gate Array, a field programmable gate array), which can be determined according to actual design requirements.

S02, the fingerprint identification substrate receives the light reflected by the finger collected by the light adjustment substrate of the fingerprint identification panel, and generates a fingerprint signal.

It should be noted that, after S02, the above control method may further include: S03, processing and identifying the fingerprint signal, S03 may be performed by the control unit, and of course may be performed by other units, which is not limited here.

For the structural description of the display device in the embodiments of the present invention, reference may be made to the above-mentioned embodiments, and details are not repeated here.

Reference herein to "one embodiment," "an embodiment," or "one or more embodiments" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present application. Also, please note that instances of the phrase "in one embodiment" herein are not necessarily all referring to the same embodiment.

In the description provided herein, numerous specific details are set forth. It will be understood, however, that the embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions recorded in the foregoing embodiments, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. The fingerprint identification panel is applied to a display device, and the display device comprises a display panel; the fingerprint identification panel is positioned on one side of the display panel, which is far away from the display side;

the fingerprint identification panel comprises a fingerprint identification substrate and a dimming substrate, and the dimming substrate is arranged between the fingerprint identification substrate and the display panel; the dimming substrate comprises a first substrate, a second substrate and a liquid crystal layer, and the liquid crystal layer is arranged between the first substrate and the second substrate; light rays emitted by the display panel are reflected by a finger under a fingerprint identification state, then sequentially pass through the first substrate and the liquid crystal layer, and sequentially irradiate towards the second substrate and the fingerprint identification substrate;

the first substrate includes a first substrate and a first electrode, the first electrode is disposed between the first substrate and the liquid crystal layer, the second substrate includes a second substrate and a second electrode, the second electrode is disposed between the second substrate and the liquid crystal layer, at least one of the first electrode and the second electrode includes a plurality of discrete sub-electrodes;

the liquid crystal layer is configured to: the light rays emitted to the fingerprint identification substrate can be converged in the fingerprint identification state.

2. The fingerprint identification panel of claim 1, the first electrode comprising a plurality of discrete sub-electrodes; the second electrode is arranged in a whole layer.

3. The fingerprint recognition panel of claim 2, wherein the first substrate further comprises a first alignment film disposed between the first electrode and the liquid crystal layer; the second substrate further includes a second alignment film disposed between the second electrode and the liquid crystal layer;

the first alignment film and the second alignment film are configured to: under the condition that the first electrode and the second electrode do not generate an electric field, the liquid crystal layer does not converge light rays emitted to the fingerprint identification substrate under the non-fingerprint identification state under the combined action;

the first and second electrodes are configured to: and generating an electric field, and enabling the liquid crystal layer to collect the light rays emitted to the fingerprint identification substrate in the fingerprint identification state.

4. The fingerprint identification panel of claim 3, wherein the second substrate further comprises a filter layer disposed between the second substrate and the second alignment film.

5. The fingerprint recognition panel of claim 1, wherein the fingerprint recognition substrate comprises a third substrate, and a first flat layer, a fingerprint recognition unit, a second flat layer and a passivation layer sequentially stacked over the third substrate;

the fingerprint identification unit includes a third electrode, a photodiode, and a fourth electrode sequentially stacked over the first planarization layer, the photodiode configured to: and receiving the light converged by the liquid crystal layer in the fingerprint identification state, and generating a fingerprint signal.

6. The fingerprint identification panel of claim 5, wherein the fingerprint identification substrate further comprises a control unit configured to: controlling the photodiode to be turned on or off;

the fingerprint identification substrate further comprises a first thin film transistor and a second thin film transistor which are arranged on the same layer, and the first thin film transistor is arranged between the third substrate and the first flat layer;

the first thin film transistor and the second thin film transistor respectively comprise an active layer, a grid electrode, a source electrode and a drain electrode;

the first electrode of the dimming substrate is electrically connected with the drain electrode of the first thin film transistor sequentially through the passivation layer and the through hole in the second flat layer; the photodiode is electrically connected with the drain electrode of the second thin film transistor through the through hole on the first flat layer, and the photodiode is electrically connected with the control unit.

7. The fingerprint recognition panel of claim 6, wherein the second substrate further comprises a black matrix disposed between the second substrate and the second electrode, and an orthogonal projection of the black matrix on the fingerprint recognition substrate does not overlap or partially overlaps an orthogonal projection of the photodiode on the fingerprint recognition substrate.

8. A display device comprising a display panel and the fingerprint recognition panel of any one of claims 1 to 7;

the fingerprint identification panel is located on one side of the display panel, which is far away from the display side.

9. The display device according to claim 8, further comprising a driving module electrically connected to the first electrode and the second electrode, respectively; the driving module is configured to provide control voltage to the first electrode and the second electrode, so that the liquid crystal layer of the fingerprint identification panel can collect light rays emitted to the fingerprint identification substrate in a fingerprint identification state.

10. A method of controlling a fingerprint recognition panel according to any one of claims 1-7, wherein said fingerprint recognition panel comprises a control unit;

the control method comprises the following steps:

the control unit inputs an opening signal to a fingerprint identification substrate of the fingerprint identification panel;

the fingerprint identification substrate receives light reflected by a finger converged by the dimming substrate of the fingerprint identification panel and generates a fingerprint signal.

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