CN108415188B

CN108415188B - Liquid crystal display panel, display device and fingerprint unlocking method thereof

Info

Publication number: CN108415188B
Application number: CN201810410811.7A
Authority: CN
Inventors: 蔡敏; 秦丹丹; 夏志强
Original assignee: Shanghai AVIC Optoelectronics Co Ltd
Current assignee: Shanghai AVIC Optoelectronics Co Ltd
Priority date: 2018-05-02
Filing date: 2018-05-02
Publication date: 2021-11-16
Anticipated expiration: 2038-05-02
Also published as: CN108415188A

Abstract

The invention provides a liquid crystal display panel, a display device and a fingerprint unlocking method thereof, relating to the technical field of display, wherein the liquid crystal display panel comprises: a display area and a non-display area surrounding the display area; the display area includes a light-shielding area and a plurality of sub-pixel opening areas, each of which is surrounded by the light-shielding area; at least one of the plurality of sub-pixel opening areas is a white sub-pixel opening area; the color film substrate comprises a substrate and a black matrix, wherein the black matrix is positioned on one side of the substrate facing the array substrate, and the black matrix is positioned in a shading area; the semiconductor photoelectric detector is positioned in the shading area surrounding the opening area of the white sub-pixel and is arranged on one side of the black matrix far away from the array substrate; the distance between the semiconductor photoelectric detector and the opening area of the white sub-pixel is less than 5 μm. The invention enhances the intensity of the fingerprint signal light and improves the accuracy of fingerprint identification.

Description

Liquid crystal display panel, display device and fingerprint unlocking method thereof

Technical Field

The invention relates to the technical field of display, in particular to a liquid crystal display panel, a display device and a fingerprint unlocking method of the liquid crystal display panel.

Background

Fingerprints are unique to everyone, as they are native to everyone. With the development of science and technology, a variety of display devices with fingerprint identification functions appear in the market, such as mobile phones, tablet computers, intelligent wearable devices and the like. Like this, the user just needs to touch display device's specific area with the finger before the operation has the display device of fingerprint identification function, just can carry out the authority through the discernment of fingerprint identification module and verify, has simplified the authority verification process. The fingerprint identification can comprise light sensation fingerprint identification, ultrasonic fingerprint identification and the like according to the working principle.

When carrying out light sense fingerprint identification, the light that the backlight sent hinders (including red look hinders, green look hinders and blue look hinders) when liquid crystal display panel's colour, and the colour hinders the light of having absorbed the partial wave band in the light, has reduced the light intensity that shines touch subject (finger), and then has reduced the light intensity that the fingerprint identification module received the light of touch subject reflection, and the intensity of fingerprint signal light is less promptly, has reduced fingerprint identification's accuracy.

Disclosure of Invention

The invention provides a liquid crystal display panel, a display device and a fingerprint unlocking method thereof, which are used for enhancing the intensity of fingerprint signal light and improving the accuracy of fingerprint identification.

In a first aspect, an embodiment of the present invention provides a liquid crystal display panel, including:

a display area and a non-display area surrounding the display area;

the display area includes a light-shielding area and a plurality of sub-pixel opening areas, each of which is surrounded by the light-shielding area;

at least one of the plurality of sub-pixel opening areas is a white sub-pixel opening area;

the color film substrate and the array substrate are oppositely arranged, the color film substrate comprises a substrate and a black matrix, the black matrix is positioned on one side, facing the array substrate, of the substrate, and the black matrix is positioned in the shading area;

the semiconductor photoelectric detector is positioned in the shading area surrounding the white sub-pixel opening area and is arranged on one side, away from the array substrate, of the black matrix;

the distance between the semiconductor photoelectric detector and the opening area of the white sub-pixel is less than 5 μm.

In a second aspect, an embodiment of the present invention provides a display device, including the liquid crystal display panel described in the first aspect;

the display device further comprises a backlight module, wherein the backlight module comprises a display light source and a photoelectric detection light source, and light emitted by the photoelectric detection light source comprises invisible light.

In a third aspect, an embodiment of the present invention provides a fingerprint unlocking method for a display device according to the second aspect, where the fingerprint unlocking method includes a fingerprint identification process, and the fingerprint identification process includes:

turning on a photoelectric detection light source, keeping a display light source off, turning on a display driving circuit to control the white sub-pixel opening area to transmit light, and turning on a fingerprint unlocking driving circuit;

the light emitted by the photoelectric detection light source passes through the white sub-pixel opening area and then irradiates the touch main body;

the light reflected by the touch main body irradiates the semiconductor photoelectric detector, and the semiconductor photoelectric detector performs photoelectric conversion according to the received light to realize fingerprint identification.

The embodiment of the invention provides a liquid crystal display panel which comprises a plurality of luminous sub-pixel opening areas and a non-luminous shading area, wherein the plurality of luminous sub-pixel opening areas can be arranged in an array mode, and the shading area is arranged between any two sub-pixel opening areas. The liquid crystal display panel further comprises a semiconductor photoelectric detector used for realizing fingerprint identification, and the semiconductor photoelectric detector is located in the shading area, so that light emitted by the sub-pixel opening area can not be shaded, and influence on normal luminous display can not be caused. The plurality of sub-pixel opening areas comprise white sub-pixel opening areas, the white sub-pixel opening areas emit white light, light emitted by the backlight source is not filtered, and the light emitted by the backlight source is emitted out of the liquid crystal display panel in the white sub-pixel opening areas without loss, so that the intensity of fingerprint signal light is enhanced, and the accuracy of fingerprint identification is improved.

Drawings

Fig. 1 is a schematic top view of an lcd panel according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view along the direction AA' in FIG. 1;

fig. 3 is a circuit diagram of a semiconductor photodetector according to an embodiment of the present invention;

fig. 4 is a schematic partial structural diagram of a semiconductor photodetector according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a top view structure of another LCD panel according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a top view structure of another LCD panel according to an embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view illustrating another LCD panel according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a top view structure of another LCD panel according to an embodiment of the present invention;

fig. 9 is a schematic top view of another lcd panel according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a top view structure of another LCD panel according to an embodiment of the present invention;

FIG. 11 is a schematic cross-sectional view illustrating another LCD panel according to an embodiment of the present invention;

fig. 12 is a schematic top view of a touch functional layer according to an embodiment of the present invention;

fig. 13 is a schematic top view of another touch functional layer according to an embodiment of the present invention;

fig. 14 is a schematic top view illustrating a functional touch layer according to another embodiment of the present invention;

fig. 15 is a schematic structural diagram of a display device according to an embodiment of the present invention;

fig. 16 is a flowchart of a fingerprint unlocking method for a display device according to an embodiment of the present invention;

fig. 17 is a flowchart of another fingerprint unlocking method for a display device according to an embodiment of the present invention;

fig. 18 is a flowchart of another fingerprint unlocking method for a display device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic top view of an lcd panel according to an embodiment of the present invention, and fig. 2 is a schematic cross-sectional view along the direction AA' in fig. 1. referring to fig. 1 and fig. 2, the lcd panel includes a display area 110 and a non-display area 120 surrounding the display area 110. The display region 110 includes a light-shielding region 130 and a plurality of sub-pixel opening regions 140, each of the sub-pixel opening regions 140 is surrounded by the light-shielding region 130, and the sub-pixel opening regions 140 are regions where the sub-pixels are located. At least one of the plurality of sub-pixel opening areas 140 is a white sub-pixel opening area 144. The liquid crystal display panel comprises a color film substrate 10 and an array substrate 20, the color film substrate 10 and the array substrate 20 are arranged oppositely, the color film substrate 10 comprises a substrate 11 and a black matrix 12, the black matrix 12 is located on one side of the substrate 11 facing the array substrate 20, and the black matrix 12 is located in a shading area 130. The liquid crystal display panel further includes a semiconductor photodetector 30, the semiconductor photodetector 30 is located in the light-shielding region 130 surrounding the white sub-pixel opening region 144 and is disposed on a side of the black matrix 12 away from the array substrate 20, light emitted from the backlight passes through the array substrate 20 and is shielded by the black matrix 12, so that the light cannot directly irradiate on the semiconductor photodetector 30, and light reflected by the touch subject Z (fingerprint) can irradiate on the semiconductor photodetector 30, thereby improving accuracy of fingerprint identification. The light emitted from the white sub-pixel opening area 144 is reflected by the touch subject Z and then carries fingerprint information (which may be referred to as fingerprint signal light), and the semiconductor photodetector 30 can perform fingerprint recognition according to the received fingerprint signal light. In general, since the emission luminance of the liquid crystal display panel gradually decreases with an increase in the angle, the fingerprint signal light having a sufficient light intensity is mainly concentrated in the vicinity of the white sub-pixel opening area 144, and it has been found from the study that the distance H between the semiconductor photodetector 30 and the white sub-pixel opening area 144 may be set to be less than 5 μm in order to make the fingerprint signal light received by the semiconductor photodetector 30 have a sufficient light intensity. Here, the distance H between the semiconductor photodetector 30 and the white sub-pixel opening area 144 refers to a distance H between one side edge of the semiconductor photodetector 30 close to the white sub-pixel opening area 144 and one side edge of the white sub-pixel opening area 144 close to the semiconductor photodetector 30, that is, a width of a gap between two patterns formed by orthographically projecting the semiconductor photodetector 30 and the white sub-pixel opening area 144 on the substrate 11. It should be noted that, for space reasons, fig. 1 exemplarily shows a plurality of sub-pixel opening areas 140 and a plurality of semiconductor photodetectors 30, and the plurality of sub-pixel opening areas 140 are arranged in an array along a first direction and a second direction, but the actual liquid crystal display panel product is not limited thereto.

Referring to fig. 1 and 2, although the closer the distance between the semiconductor photodetector 30 and the white sub-pixel opening area 144 is, the stronger the light intensity of the fingerprint signal light received by the semiconductor photodetector 30 is, the color filter substrate 10 and the array substrate 20 often have a certain alignment deviation, which leads to light leakage at the edges of the sub-pixels, and in order to avoid the light leakage at the edges of the sub-pixels from directly irradiating the semiconductor photodetector 30, the distance H between the semiconductor photodetector 30 and the white sub-pixel opening area 144 may be set to satisfy 1 μm or more and H or less than 5 μm.

Alternatively, referring to fig. 1 and 2, the plurality of sub-pixel opening areas 140 may further include a red sub-pixel opening area 141, a green sub-pixel opening area 142, and a blue sub-pixel opening area 143. The color filter substrate 10 may include a plurality of color resistors 40, and the plurality of color resistors 40 may include a red color resistor 41, a green color resistor 42, a blue color resistor 43, and a white color resistor 44. The red color resist 41 is located in the red sub-pixel opening area 141, the green color resist 42 is located in the green sub-pixel opening area 142, the blue color resist 43 is located in the blue sub-pixel opening area 143, and the white color resist 44 is located in the white sub-pixel opening area 144. The red, green and blue color resists 41, 42 and 43 respectively display red, green and blue colors by filtering specific wavelength bands in the white light, and the white resist 44 has no absorption and wavelength band filtering effects on the white light. The light emitted from the red sub-pixel opening area 141 is red light, the light emitted from the green sub-pixel opening area 142 is green light, the light emitted from the blue sub-pixel opening area 143 is blue light, and the light emitted from the white sub-pixel opening area 144 is white light. The color filter substrate 10 may further include a planarization layer 13, where the planarization layer 13 is located on a side of the black matrix 12 away from the substrate 11 and covers the black matrix 12 and the color resistor 40, so as to provide a flat surface for a subsequent alignment film formed on a side of the color filter substrate 10 close to the array substrate 20. The planarization layer 13 is generally made of a transparent organic material, and the white color resists 44 can be formed in the same process as the planarization layer 13, that is, the white color resists 44 can be formed by filling the openings surrounded by the black matrix 12 in the white sub-pixel opening areas 144 with the organic material when the planarization layer 13 is formed.

Fig. 3 is a circuit diagram of a semiconductor photodetector according to an embodiment of the present invention, where the semiconductor photodetector includes a photodiode 34, a storage capacitor C, and a thin film transistor T, an anode of the photodiode 34 is electrically connected to a first plate of the storage capacitor C, and a cathode of the photodiode 34 is electrically connected to a second plate of the storage capacitor C and a source of the thin film transistor T. The Gate of the thin film transistor T is electrically connected to the switch control line Gate, and the drain of the thin film transistor T is electrically connected to the signal detection line Data. The photodiode 34 is used to optically convert the fingerprint signal into a current signal. In the fingerprint identification stage, the switch control line Gate controls the thin film transistor T to be turned on, and the current signal is transmitted to the signal detection line Data through the thin film transistor T, so as to perform fingerprint identification according to the current signal.

Fig. 4 is a schematic partial structural diagram of a semiconductor photodetector according to an embodiment of the present invention, and referring to fig. 3 and 4, the semiconductor photodetector 30 includes a photodiode 34, and the photodiode 34 sequentially includes a first electrode 31, a PIN junction 32, and a second electrode 33 along a direction away from the array substrate 20.

Specifically, referring to fig. 3 and 4, the first electrode 31 may be an anode of the photodiode D, the second electrode 33 may be a cathode of the photodiode D, the second electrode 33 may be formed using an Indium Tin Oxide (ITO) material, reflected light reflected by a finger fingerprint passes through the second electrode 33 and then is irradiated onto the PIN junction 32, and the PIN junction 32 has a photosensitive characteristic and has unidirectional conductivity. In the absence of light, the PIN junction 32 has a small saturation reverse leakage current, i.e., dark current, at which the photodiode D is turned off. When exposed to light, the saturation reverse leakage current of the PIN junction 32 increases substantially, forming a photocurrent. The PIN junction 32 may be composed of a P-type semiconductor layer 321, an intrinsic semiconductor layer 322, and an N-type semiconductor layer 323, the intrinsic semiconductor layer 322 being located between the P-type semiconductor layer 321 and the N-type semiconductor layer 323, wherein the P-type semiconductor layer 321 may be in direct contact with the second electrode 33, and the N-type semiconductor layer 323 may be in direct contact with the first electrode 31. In addition, the embodiment of the invention does not limit the specific stacking manner of the first electrode 31, the P-type semiconductor layer 321, the intrinsic semiconductor layer 322, the N-type semiconductor layer 323, and the second electrode 33.

Alternatively, referring to fig. 4, both ends of the PIN junction 32 are electrically connected to the first electrode 31 and the second electrode 33, respectively, and the first electrode 31 and the second electrode 33 are transparent electrodes, respectively.

Specifically, since the semiconductor photodetector 30 is located on the side of the black matrix 12 away from the array substrate 20, light emitted from the backlight source is shielded by the black matrix 12 after passing through the array substrate 20, and thus cannot be directly irradiated onto the semiconductor photodetector 30, and both the first electrode 31 and the second electrode 33 are transparent electrodes, so that normal use of the semiconductor photodetector 30 is not affected, and since both the first electrode 31 and the second electrode 33 are transparent electrodes, the first electrode 31 and the second electrode 33 can be formed by using the same material, for example, both the first electrode 31 and the second electrode 33 can be formed by using Indium Tin Oxide (ITO) material, so as to simplify the process, and reduce the production and design costs.

FIG. 5 is a schematic diagram of a top view structure of another LCD panel according to an embodiment of the present invention, referring to FIGS. 4 and 5, along a first direction, a PIN junction 32 can be simultaneously located near a plurality of white sub-pixel opening areas 144; in the second direction, one PIN junction 32 may be simultaneously located in the vicinity of a plurality of white sub-pixel opening areas 144. Since the semiconductor photodetector 30 mainly relies on the photodiode 34 to receive the fingerprint signal light and convert the light signal into an electrical signal for fingerprint recognition, the area occupied by the photodiode 34 in the light-shielding region 130 is substantially the area occupied by the semiconductor photodetector 30 in the light-shielding region 130. Thus, in the first direction, one semiconductor photodetector 30 may be simultaneously located in the vicinity of the plurality of white sub-pixel opening areas 144; in the second direction, one semiconductor photodetector 30 may be simultaneously located in the vicinity of the plurality of white sub-pixel opening areas 144. In the embodiment of the present invention, the semiconductor photodetector 30 is disposed on the side of the black matrix 12 away from the array substrate 20, the semiconductor photodetector 30 is not disposed on the array substrate 20, and the distribution of the PIN junctions 32 in the semiconductor photodetector 30 is not affected by the arrangement of data lines and scan lines, for example, so that the PIN junctions 32 for receiving the fingerprint signal light in the embodiment of the present invention can be made large enough under the condition of ensuring the resolution (as shown in fig. 5, the PIN junctions 32 may be in a grid structure in a schematic plan view), so that one PIN junction 32 receives the reflected light passing through the plurality of white sub-pixel opening areas 144 at the same time, thereby enhancing the intensity of the fingerprint signal light and improving the accuracy of fingerprint identification.

Referring to fig. 6, the edge of the white sub-pixel opening area 144 includes at least one notch 1440 (an exemplary notch 1440 is disposed in fig. 6), at least two edges of the notch 1440 coincide with the edge of the white sub-pixel opening area 144, and at least a portion of the semiconductor photodetector 30 is located in the notch 1440, according to another schematic top view structure of the liquid crystal display panel provided by the embodiment of the present invention. In the embodiment of the present invention, at least one notch 1440 is disposed on the edge of the white sub-pixel opening area 144, and at least a portion of the semiconductor photodetector 30 is disposed in the notch 1440, so that the semiconductor photodetector 30 is simultaneously close to the white sub-pixel opening area 144 in two different directions, and thus the semiconductor photodetector 30 receives fingerprint signal light with a larger intensity, thereby improving the accuracy of fingerprint identification.

Specifically, referring to fig. 1 and 6, in the first direction, the semiconductor photodetector 30 is located in the vicinity of the white sub-pixel opening area 144, and the distance H1 between one side edge of the semiconductor photodetector 30 close to the white sub-pixel opening area 144 and one side edge of the white sub-pixel opening area 144 close to the semiconductor photodetector 30; in the second direction, the semiconductor photodetector 30 is positioned adjacent the white sub-pixel opening area 144, and the distance H2 between an edge of the semiconductor photodetector 30 adjacent the white sub-pixel opening area 144 and an edge of the white sub-pixel opening area 144 adjacent the semiconductor photodetector 30. The semiconductor photodetector 30 is spaced from the white sub-pixel opening area 144 by a distance H of less than 5 μm, i.e., H1 < 5 μm, and/or H2 < 5 μm.

Alternatively, referring to fig. 2, the semiconductor photodetector 30 is located between the substrate base plate 11 and the black matrix 12. That is, the semiconductor photodetector 30 is disposed on the color filter substrate 10. Generally, the color filter substrate 10 has fewer film structures and circuit structures than the array substrate 20, so that when the semiconductor photodetector 30 is disposed on the color filter substrate 10, the semiconductor photodetector 30 can be directly formed on the substrate 11, and a complicated design is not required to avoid interference with other film structures and circuit structures, which is simple and convenient.

Fig. 7 is a schematic cross-sectional structure view of another liquid crystal display panel according to an embodiment of the present invention, referring to fig. 7, the liquid crystal display panel further includes a protective cover 60, the protective cover 60 is located on a side of the color filter substrate 10 away from the array substrate 20, and the protective cover 60 and the color filter substrate 10 are bonded and fixed by a bonding layer 50, where the bonding layer 50 may be, for example, an optically transparent adhesive. The semiconductor photodetector 30 may also be disposed on a side of the protective cover 60 facing the color filter substrate 10, that is, the semiconductor photodetector 30 is formed on the protective cover 60. This has the advantage that when the semiconductor photodetector 30 has a yield problem, the protective cover 60 with the semiconductor photodetector 30 can be directly discarded, and since other structures such as color resists are not formed on the protective cover 60, the economic loss is small.

Fig. 8 is a schematic top view of another lcd panel according to an embodiment of the present invention, and referring to fig. 8, at least two semiconductor photodetectors 30 are located in the light shielding region 130 surrounding the same white sub-pixel opening region 144 (for example, three semiconductor photodetectors 30 are located near one white sub-pixel opening region 144 in fig. 8, and for clarity, one white sub-pixel opening region 144 and three semiconductor photodetectors 30 are indicated by dashed boxes in fig. 8). The larger the number of semiconductor photodetectors 30 disposed in the vicinity of one white sub-pixel opening area 144, the larger the range of received fingerprint signal light, thereby enabling more accurate fingerprint recognition. The present embodiment further improves the accuracy of fingerprint identification by placing multiple semiconductor photodetectors 30 in the light-blocking region 130 surrounding the same white sub-pixel opening region 144.

Alternatively, referring to fig. 8, at most one semiconductor photodetector 30 is disposed at each side of the white sub-pixel opening area 144. For the same number of semiconductor photodetectors 30, if a plurality of semiconductor photodetectors 30 are disposed on one side of one edge of the white sub-pixel opening area 144, no semiconductor photodetector 30 is disposed at the other edge of the white sub-pixel opening area 144, and the fingerprint signal light cannot be received; therefore, at most one semiconductor photodetector 30 is disposed on each side of the white sub-pixel opening area 144, and all the semiconductor photodetectors 30 can receive more fingerprint signal light on the premise of the same number of semiconductor photodetectors 30, thereby improving the accuracy of fingerprint identification.

Fig. 9 is a schematic top view of another lcd panel according to an embodiment of the present invention, and referring to fig. 9, the lcd panel includes a plurality of semiconductor photodetectors 30, and the plurality of semiconductor photodetectors 30 are regularly distributed in a display area 110.

Specifically, referring to fig. 9, a plurality of semiconductor photodetectors 30 may be uniformly distributed within the display area 110. In the display area 110, the number of the semiconductor photodetectors 30 in two arbitrarily selected regions having equal areas is equal, and the semiconductor photodetectors 30 fill the entire display area 110. Therefore, fingerprint identification can be realized at any position in the display area 110, which is beneficial to improving user experience.

Fig. 10 is a schematic top view of another liquid crystal display panel according to an embodiment of the present invention, referring to fig. 10, the display area 110 includes a fingerprint unlocking area 150, an area of the fingerprint unlocking area 150 is smaller than that of the display area 110, the fingerprint unlocking area 150 is only a portion of the display area 110, the semiconductor photodetector 30 is only located in the fingerprint unlocking area 150, and the semiconductor photodetector 30 is not located outside the fingerprint unlocking area 150. All the semiconductor photodetectors 30 are arranged in the fingerprint unlocking region 150 in a concentrated manner, so that the number of the semiconductor photodetectors 30 can be reduced, and the manufacturing cost of the liquid crystal display panel is reduced.

Fig. 11 is a schematic cross-sectional structure view of another liquid crystal display panel according to an embodiment of the present invention, and referring to fig. 11, the liquid crystal display panel further includes a touch functional layer 70, where the touch functional layer 70 is used for detecting a touch position. In the embodiment of the present invention, the touch functional layer 70 is disposed on a side of the color film substrate 10 away from the array substrate 20, and in other embodiments, the touch functional layer 70 may also be disposed on a side of the color film substrate 10 close to the array substrate 20 or a side of the array substrate 20 close to the color film substrate 10. The touch function layer 70 may include a plurality of touch electrodes, and the touch electrodes are used to detect the touch position, and some optional touch function layer setting modes are given below in combination with the types of the touch electrodes.

Fig. 12 is a schematic top view structure diagram of a touch functional layer according to an embodiment of the present invention, referring to fig. 12, a touch functional layer 70 includes a plurality of touch driving electrodes 71, a plurality of touch sensing electrodes 72, and a plurality of bridge structures 73, where the plurality of touch sensing electrodes 72 adjacent to each other in a same column are connected to each other, the plurality of touch driving electrodes 71 adjacent to each other in a same row are disconnected from each other, and the plurality of touch driving electrodes 71 in a same row are connected to each other through the bridge structures 73. The touch driving electrodes 71 can be used for receiving touch driving signals, and the touch sensing electrodes 72 can be used for generating touch sensing signals.

Fig. 13 is a schematic top view of another touch functional layer according to an embodiment of the present invention, referring to fig. 13, a touch functional layer 70 includes a plurality of touch driving electrodes 71 and a plurality of touch sensing electrodes 72, the touch sensing electrodes 71 may extend along a transverse direction and are arranged along a longitudinal direction, the touch driving electrodes 72 may extend along the longitudinal direction and are arranged along the transverse direction, and the touch sensing electrodes 71 and the touch driving electrodes 72 are crossed in an insulated manner.

Fig. 14 is a schematic top view structure diagram of another touch functional layer according to an embodiment of the present invention, which is different from the mutual capacitance type touch electrodes shown in fig. 12 and 13, in that the touch electrode shown in fig. 14 is a self-capacitance type touch electrode, and referring to fig. 14, the touch functional layer 70 includes a plurality of self-capacitance type touch electrode blocks 700 located on the same layer, and the self-capacitance type touch electrode blocks 700 are arranged in an array.

Based on the above embodiments, the distribution density of the semiconductor photodetectors 30 is optionally greater than 300/inch. If the distribution density of the semiconductor photodetectors 30 is too small, the number of semiconductor photodetectors 30 per unit area is too small, resulting in too low an accuracy of fingerprint recognition or even failure to perform a fingerprint recognition function. According to the embodiment of the invention, the distribution density of the semiconductor photoelectric detectors 30 is set to be more than 300/inch, so that the accuracy of fingerprint identification is ensured.

Fig. 15 is a schematic structural diagram of a display device according to an embodiment of the present invention, and as shown in fig. 15, a display device 100 according to an embodiment of the present invention includes a liquid crystal display panel 100 according to any embodiment of the present invention, where the liquid crystal display panel 100 includes a display area 110 and a non-display area 120. The display device further comprises a backlight module 200, wherein the backlight module 200 comprises a display light source 221 and a photoelectric detection light source 222, and light emitted by the photoelectric detection light source 222 comprises non-visible light.

Specifically, the backlight module 200 may be a side-in type backlight module, the backlight module 200 includes a light guide plate 210 and a light bar 220 located at an end surface of one side of the light guide plate 210, and the light bar 220 includes a plurality of light sources, for example, LEDs. The plurality of light-emitting sources are classified into two types, a display light source 221 and an optoelectronic detection light source 222, the display light source 221 is used as a light source for light-emitting display, and the optoelectronic detection light source 222 is used as a light source for fingerprint identification. The display light sources 221 and the photodetection light sources 222 may be sequentially spaced along the same direction, so that the display light sources 221 are uniformly distributed on a side end surface of the light guide plate 210, and the photodetection light sources 222 are also uniformly distributed on a side end surface of the light guide plate 210, further, the light emitted from the plurality of display light sources 221 is uniformly irradiated into the light guide plate 210, and the light emitted from the plurality of photodetection light sources 222 is uniformly irradiated into the light guide plate 210. The display light sources 221 and the photodetection light sources 222 may be sequentially spaced in the same direction, for example, one or more photodetection light sources 222 may be spaced between two adjacent display light sources 221, and one or more display light sources may be spaced between two adjacent photodetection light sources 222. In addition, in fingerprint recognition, in order to improve user experience, the fingerprint signal light may be set to be not perceived by human eyes, and thus, invisible light such as ultraviolet light or infrared light may be used as a light source for fingerprint recognition.

Fig. 16 is a flowchart of a fingerprint unlocking method for a display device according to an embodiment of the present invention, and referring to fig. 1, fig. 2, fig. 15, and fig. 16, the fingerprint unlocking method includes a fingerprint identification process, and the fingerprint identification process includes the following steps:

s110, turning on the photo-detection light source 222, keeping the display light source 221 off, turning on the display driving circuit (not shown) to control the white sub-pixel opening area 144 to transmit light, and turning on the fingerprint unlocking driving circuit (not shown).

The photodetection light source 222 is turned on, and the photodetection light source 222 emits invisible light. The display driver circuit is turned on, which can drive the liquid crystal molecules to rotate so that the white sub-pixel opening area 144 transmits light, and optionally, the display driver circuit can drive the liquid crystal molecules to rotate so that the red sub-pixel opening area 141, the green sub-pixel opening area 142, and the blue sub-pixel opening area 143 do not transmit light. And starting the fingerprint unlocking driving circuit, wherein the fingerprint unlocking driving circuit can be electrically connected with the switch control line Gate and the signal detection line Data shown in fig. 3, and drives the semiconductor photoelectric detector 30 to work. It should be noted that, in the embodiment of the present invention, the sequence of the turn-on times of the photoelectric detection light source 222, the display driving circuit, and the fingerprint unlocking driving circuit is not limited.

S120, the light emitted from the photo-detection light source 222 passes through the white sub-pixel opening area 144 and then irradiates the touch subject Z.

S130, the light reflected by the touch subject Z is irradiated onto the semiconductor photodetector 30, and the semiconductor photodetector 30 performs photoelectric conversion according to the received light, thereby realizing fingerprint recognition.

In the embodiment of the invention, the fingerprint unlocking method of the display device can be realized based on the display device provided by the embodiment. The display device comprises the liquid crystal display panel and the backlight module, the plurality of sub-pixel opening areas of the liquid crystal display panel comprise white sub-pixel opening areas, the white sub-pixel opening areas emit white light, the light emitted by the backlight source is not filtered, and the light emitted by the backlight source is emitted out of the liquid crystal display panel without loss at the white sub-pixel opening areas, so that the intensity of fingerprint signal light is enhanced, and the accuracy of fingerprint identification is improved. In addition, when the photoelectric detection light source is started, the display light source is in a closed state, and the display device does not need to display pictures, so that the fingerprint unlocking method provided by the embodiment of the invention can realize dark unlocking, and is convenient and quick.

Fig. 17 is a flowchart of another fingerprint unlocking method for a display device according to an embodiment of the present invention, and referring to fig. 9, 11-14 and 17, a plurality of semiconductor photodetectors 30 are regularly distributed in a display area 110. Before the photoelectric detection light source 222, the display driving circuit and the fingerprint unlocking driving circuit are turned on, the fingerprint unlocking method further comprises the following steps:

s1111, turning on a touch driving circuit (not shown), and determining a fingerprint identification area according to the touch position detected by the touch function layer 70.

The touch driving circuit can drive the touch electrodes (the touch driving electrode 71, the touch sensing electrode 72 or the self-capacitance touch electrode block 700) to work, so as to detect the touch position.

S1112, close the touch driving circuit and perform a fingerprint identification process in the fingerprint identification area.

The plurality of semiconductor photodetectors 30 may be evenly distributed within the display area 110. Semiconductor photodetectors 30 are distributed within the fingerprint identification area, and semiconductor photodetectors 30 are also distributed in the display area 110 outside the fingerprint identification area. In the embodiment of the present invention, before fingerprint identification is performed, the position of the touch subject is located by the touch functional layer 70, and then only the photoelectric detection light source 222, the display driving circuit and the fingerprint unlocking driving circuit at the position where the touch subject is located (i.e., the fingerprint identification area) are turned on, so that the number of driving signals is reduced, and the operation time of fingerprint unlocking is shortened.

Fig. 18 is a flowchart of another fingerprint unlocking method for a display device according to an embodiment of the present invention, referring to fig. 10, 11-14 and 18, the display area 110 includes a fingerprint unlocking region 150, the area of the fingerprint unlocking region 150 is smaller than that of the display area 110, and the semiconductor photodetector 30 is only located in the fingerprint unlocking region 150. Before the photoelectric detection light source 222, the display driving circuit and the fingerprint unlocking driving circuit are turned on, the fingerprint unlocking method further comprises the following steps:

s1121, the touch driving circuit (not shown) in the fingerprint unlocking region 150 is turned on.

Optionally, the touch driving circuit in the fingerprint unlocking area 150 may be turned on, and the touch driving circuit outside the fingerprint unlocking area 150 in the display area 110 may be turned off.

S1122, when the touch functional layer 70 detects a touch main body, the touch driving circuit is turned off, and a fingerprint identification process is performed in the fingerprint unlock region 150.

The touch function layer 70 may detect a touch position, and may also be used to monitor whether there is a touch operation, where when the touch subject touches a portion of the display device corresponding to the fingerprint unlock region 150, the touch operation triggers a fingerprint identification process in the fingerprint unlock region 150.

In the embodiment of the present invention, the semiconductor photodetector 30 is only located in the fingerprint unlocking region 150, and the semiconductor photodetector 30 is not located outside the fingerprint unlocking region 150. By disposing all the semiconductor photodetectors 30 in the fingerprint unlock region 150 in a concentrated manner, the number of semiconductor photodetectors 30 used can be reduced, and the power consumption of the liquid crystal display panel can be reduced. Alternatively, the photodetection light source 222 may be kept turned on and the fingerprint unlock drive circuit may be kept turned on before the touch drive circuit in the fingerprint unlock region 150 is turned on, while the touch drive circuit in the fingerprint unlock region 150 is turned on, and after the touch drive circuit in the fingerprint unlock region 150 is turned on. That is, the photo-detection light source 222 and the fingerprint unlocking driving circuit can be kept on all the time during the whole fingerprint unlocking process. At this time, "turning on the photoelectric detection light source 222 and turning on the fingerprint unlocking driving circuit" in step S110 should be understood as: keeping the photodetection light source 222 and the fingerprint unlock drive circuit in an on state.

In addition, after the fingerprint identification is completed and the fingerprint unlocking is successful, the photoelectric detection light source 222 and the fingerprint unlocking driving circuit can be turned off to reduce the power consumption of the liquid crystal display panel; then, the display light source 221 is turned on, the display driving circuit is turned on to control the sub-pixel opening area 140 (including the red sub-pixel opening area 141, the green sub-pixel opening area 142, the blue sub-pixel opening area and the white sub-pixel opening area 144) to transmit light, and the touch driving circuit in the display area 110 is turned on, so that the touch and display functions are realized in the whole display area 110.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A liquid crystal display panel, comprising:

a display area and a non-display area surrounding the display area;

the distance H between the semiconductor photoelectric detector and the opening area of the white sub-pixel meets the condition that H is more than or equal to 1 mu m and less than or equal to 5 mu m;

at least two semiconductor photodetectors are present, located in the light-shielding region surrounding the same white sub-pixel opening region;

each side of the white sub-pixel opening area is provided with at most one semiconductor photoelectric detector;

the semiconductor photoelectric detector comprises a photosensitive diode, and the photosensitive diode sequentially comprises a first electrode, a PIN junction and a second electrode along the direction far away from the array substrate;

in a first direction, the PIN junctions are simultaneously located in the vicinity of a plurality of the white sub-pixel opening areas; in a second direction, the PIN junctions are simultaneously located in the vicinity of a plurality of the white sub-pixel opening areas;

the first direction and the second direction are both parallel to the light-emitting surface and are mutually crossed.

2. The liquid crystal display panel of claim 1, wherein the edge of the white sub-pixel opening area comprises at least one notch, and at least two edges of the notch coincide with the edge of the white sub-pixel opening area;

the semiconductor photodetector at least partially resides within the notch.

3. The liquid crystal display panel according to claim 1, wherein the semiconductor photodetector is located between the substrate base plate and the black matrix.

4. The liquid crystal display panel according to claim 1, wherein both ends of the PIN junction are electrically connected to the first electrode and the second electrode, respectively, and the first electrode and the second electrode are transparent electrodes, respectively.

5. The liquid crystal display panel according to claim 1, comprising:

the plurality of semiconductor photoelectric detectors are regularly distributed in the display area.

6. The liquid crystal display panel of claim 1, wherein the display region comprises a fingerprint unlocking region, the fingerprint unlocking region has a smaller area than the display region, and the semiconductor photodetector is located only in the fingerprint unlocking region.

7. The liquid crystal display panel according to claim 1, further comprising a touch functional layer for touch position detection.

8. The liquid crystal display panel of claim 1, wherein the semiconductor photodetectors are distributed at a density of greater than 300/inch.

9. A display device comprising the liquid crystal display panel according to any one of claims 1 to 8;

10. A fingerprint unlocking method based on the display device of claim 9, wherein the fingerprint unlocking method comprises a fingerprint identification process, and the fingerprint identification process comprises:

11. The method of claim 10, wherein a plurality of the semiconductor photodetectors are regularly distributed within the display area;

before turning on the photoelectric detection light source, the display driving circuit and the fingerprint unlocking driving circuit, the fingerprint unlocking method further includes:

starting a touch control driving circuit, and determining a fingerprint identification area through a touch position detected by a touch control functional layer;

and closing the touch control driving circuit, and executing the fingerprint identification process in the fingerprint identification area.

12. The method of claim 10, wherein the display region comprises a fingerprint unlocking region, the fingerprint unlocking region having a smaller area than the display region, the semiconductor photodetector being located only within the fingerprint unlocking region;

starting a touch control driving circuit in the fingerprint unlocking area;

and when the touch control function layer detects a touch main body, closing the touch control driving circuit, and executing the fingerprint identification process in the fingerprint unlocking area.