CN110187544B

CN110187544B - Display device, liquid crystal display panel and driving method thereof

Info

Publication number: CN110187544B
Application number: CN201910580368.2A
Authority: CN
Inventors: 张永忠; 苏京; 程晓萍
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2022-04-19
Anticipated expiration: 2039-06-28
Also published as: CN110187544A

Abstract

The present disclosure provides a display device, a liquid crystal display panel and a driving method thereof, and relates to the field of display technology. The liquid crystal display panel includes a display module, a backlight module, a first polarizer, a second polarizer, a light guide layer, an identification light source and an identification light sensing circuit. The display module includes a liquid crystal layer and a color filter layer on one side of the liquid crystal layer. The color filter layer includes a plurality of filter regions corresponding to each sub-pixel one by one. The liquid crystal layer is used to form an identification region, and the identification region includes a plurality of and sub-pixels. The light-transmitting area corresponding to the pixel; the backlight module is arranged on the backlight side of the display module; the first polarizer is arranged on the light-incident side of the liquid crystal layer; the second polarizer is arranged on a side of the liquid crystal layer opposite to the first polarizer. side; the back side of the light guide layer is directly opposite to the display module, and the contact surface is used for contact with fingers; at least part of the light emitted by the light source and entering the light guide layer can be totally reflected between the back side and the contact surface; The circuit is arranged on the side of the first polarizer opposite to the second polarizer.

Description

Display device, liquid crystal display panel and driving method thereof

Technical Field

The disclosure relates to the technical field of display, in particular to a display device, a liquid crystal display panel and a driving method of the liquid crystal display panel.

Background

At present, the technology of implementing fingerprint identification on a display panel is widely applied, wherein the display panel with the fingerprint identification function is usually an OLED (Organic Light-Emitting Diode) display panel, and Light emitted by an Organic Light-Emitting layer is reflected by a fingerprint and then reaches a fingerprint identification device through a small hole on a Light shielding layer located on a side of the Organic Light-Emitting layer away from a finger, so as to obtain fingerprint information. However, if a light-shielding layer having small holes is disposed in the liquid crystal display panel, the light-shielding layer may shield the light of the backlight module, thereby making it difficult to display an image, which makes it difficult to apply the fingerprint recognition technology to the liquid crystal display panel.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The present disclosure is directed to overcome the above-mentioned deficiencies of the prior art, and provides a display device, a liquid crystal display panel and a driving method of the liquid crystal display panel, which can realize fingerprint identification based on pinhole imaging in the liquid crystal display panel.

According to an aspect of the present disclosure, there is provided a liquid crystal display panel including a plurality of sub-pixels, the liquid crystal display panel including:

the display module comprises a liquid crystal layer and a color film layer positioned on one side of the liquid crystal layer, wherein the color film layer comprises a plurality of filter areas which correspond to the sub-pixels one by one, the liquid crystal layer is used for forming an identification area, and the identification area comprises a plurality of light transmission areas corresponding to the sub-pixels;

the backlight module is arranged on the backlight side of the display module;

the first polaroid is arranged on the light incident side of the liquid crystal layer;

the second polaroid is arranged on one side of the liquid crystal layer, which is opposite to the first polaroid;

the light guide layer is provided with a contact surface and a back surface which are opposite to each other, the back surface is arranged opposite to the display module, and the contact surface is used for being in contact with fingers;

the identification light source is used for emitting light to the light guide layer, and at least part of the light entering the light guide layer can be totally reflected between the back surface and the contact surface;

the identification light sensing circuit is arranged on one side of the first polaroid, which is opposite to the second polaroid, and is used for sensing the light of the identification light source and generating a fingerprint signal, and the identification light sensing circuit is of a transparent structure;

at least part of light rays emitted by the identification light source can reach the identification light sensing circuit through the color film layer, the transparent area and the first polarizer after being reflected by the finger, so that a fingerprint image is formed on the identification light sensing circuit.

In an exemplary embodiment of the present disclosure, an outline of the sub-pixel corresponding to the light-transmitting region is square or circular, and an area of the sub-pixel is smaller than an area of the sub-pixel not corresponding to the light-transmitting region.

In an exemplary embodiment of the disclosure, the sub-pixel corresponding to the light-transmitting area and the sub-pixel directly adjacent to the sub-pixel in the row or column direction are of the same color, and an area of the sub-pixel directly adjacent to the sub-pixel corresponding to the light-transmitting area is larger than an area of the sub-pixel not directly adjacent to the sub-pixel.

In an exemplary embodiment of the present disclosure, the sub-pixel corresponding to the light-transmitting region is configured to emit white light.

In an exemplary embodiment of the disclosure, corresponding ranges of the finger reflected light received by two adjacent light-transmitting areas on the contact surface are at least partially overlapped; the ranges of the light rays penetrating through the two adjacent light-transmitting areas on the identification light ray induction circuit are not coincident.

In an exemplary embodiment of the disclosure, the range of the identification area is the same as the range of the liquid crystal layer, the light-transmitting areas are uniformly distributed in the identification area, and the projection of the identification light sensing circuit on the liquid crystal layer is opposite to the identification area.

In an exemplary embodiment of the present disclosure, the backlight module is a direct type backlight module or a side type backlight module;

if the backlight module is a direct type backlight module, the backlight module comprises a plurality of backlight sources facing the display module, and at least part of the backlight sources correspond to the identification area; the backlight corresponding to the identification area emits light with a first luminous intensity, and the backlight corresponding to the area outside the identification area emits light with a second luminous intensity; the product of the first luminous intensity and the light transmittance of the identification light sensing circuit is equal to the second luminous intensity;

if the backlight module is a side-in type backlight module, the backlight module comprises a light guide plate, the light guide plate is provided with a light-emitting surface and a backlight surface which are opposite, the light-emitting surface faces the display module, and the backlight surface is provided with reflective mesh points; the density of the screen dots of the backlight surface corresponding to the area of the identification area is a first density, and the density of the screen dots of the backlight surface corresponding to the area outside the identification area is a second density; the first density is greater than the second density.

In an exemplary embodiment of the present disclosure, further comprising:

the touch control module is arranged between the light guide layer and the display module and used for judging the touch control position of the finger so as to control the identification light induction circuit to generate a fingerprint signal according to the received light when the touch control position is positioned in the identification area.

According to an aspect of the present disclosure, there is provided a driving method of a liquid crystal display panel, for the liquid crystal display panel described in any one of the above, including:

in the fingerprint identification period:

emitting light to the light guide layer, and at least closing a light source of the backlight module corresponding to the identification area;

controlling the identification area of the liquid crystal layer to form a plurality of light-transmitting areas;

controlling the identification light sensing circuit to generate a fingerprint signal according to the received light;

in the display period:

opening the backlight module;

and controlling the identification area of the liquid crystal layer to be in a normal display state.

In an exemplary embodiment of the present disclosure, the liquid crystal display panel further includes:

the touch module is arranged on one side, facing the backlight module, of the light guide layer;

the driving method further includes:

and judging the touch position of the finger, and entering the fingerprint identification time period when the touch position is located in the identification area.

According to an aspect of the present disclosure, there is provided a display device including the liquid crystal display panel described in any one of the above.

In an exemplary embodiment of the present disclosure, the display module is provided with a mounting hole penetrating in a direction perpendicular to the contact surface, and the identification light source is disposed in the mounting hole;

the display device further includes:

and the camera shooting module is arranged in the mounting hole.

The display device, the liquid crystal display panel and the driving method of the liquid crystal display panel can at least close a light source corresponding to a backlight module and an identification area when fingerprint identification is carried out, and the identification light source emits identification light rays into a light guide layer; when a finger is not in contact with the area of the contact layer corresponding to the identification area, light in the light guide layer is totally reflected on the contact surface and the back surface; when a finger contacts with the contact layer corresponding to the area of the identification area, the total reflection condition of the contact area is destroyed, so that light can be emitted to the finger from the contact area and is reflected by the finger, when the light reflected by the finger irradiates the back of the light guide layer, the incident angle of at least part of the light does not meet the total reflection condition, so that the light can irradiate to the identification light sensing circuit after penetrating through the filter area and the first polaroid, and a fingerprint image is formed on the identification light sensing circuit according to the pinhole imaging principle, so that fingerprint information can be identified.

When the image is displayed, the backlight module can be opened, the identification area of the liquid crystal layer can be controlled to be in a conventional display state, the light-transmitting area does not exist, the image can be normally displayed, and the identification light sensing circuit cannot shield light rays emitted by the backlight module. Thus, fingerprint recognition can be performed on the liquid crystal display panel.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

Fig. 1 is a schematic view of a liquid crystal display panel according to an embodiment of the present disclosure when a finger is not in contact with the liquid crystal display panel during a fingerprint identification period.

Fig. 2 is a schematic diagram of a liquid crystal display panel in contact with a finger during a fingerprint identification period according to an embodiment of the present disclosure.

Fig. 3 is a schematic diagram of a liquid crystal display panel according to an embodiment of the present disclosure during a display period.

Fig. 4 is a schematic view of a local distribution of a filter region of a liquid crystal display panel according to an embodiment of the disclosure.

Fig. 5 is a schematic view illustrating a display module of a liquid crystal display panel according to an embodiment of the disclosure having a mounting hole.

Fig. 6 is a schematic view illustrating a distribution of dots of a light guide plate of a lateral backlight module of a liquid crystal display panel according to an embodiment of the disclosure.

Fig. 7 is a schematic distribution diagram of a backlight source of a direct-type backlight module of a liquid crystal display panel according to an embodiment of the disclosure.

Description of reference numerals:

1. a display module; 11. a liquid crystal layer; 111. a light-transmitting region; 101. mounting holes; 12. a color film layer; 121. a light filtering area; 122. a black matrix; 13. an array substrate; 14. a color film substrate; 141. a second substrate; 15. a pixel electrode; 16. a common electrode; 2. a backlight module; 21. a light guide plate; 22. a backlight source; 3. a light guide layer; 31. a contact surface; 32. a light incident surface; 4. identifying a light source; 5. a light ray sensing circuit is identified; 6. a first polarizer; 7. a second polarizer; 8. a touch module; 100. the camera module.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first" and "second" are used merely as labels, and are not limiting on the number of their objects.

The disclosed embodiment provides a liquid crystal display panel, which comprises a plurality of sub-pixels, as shown in fig. 1-3, the liquid crystal display panel comprises a display module 1, a backlight module 2, a light guide layer 3, an identification light source 4, an identification light induction circuit 5, a first polarizer 6 and a second polarizer 7, wherein:

the display module 1 includes a liquid crystal layer 11 and a color film layer 12 located on one side of the liquid crystal layer 11, the color film layer 12 includes a plurality of filter regions 121 corresponding to the sub-pixels one by one, the liquid crystal layer 11 is used to form an identification region, the identification region includes a plurality of light transmission regions 111 corresponding to the sub-pixels, and each light transmission region 111 corresponds to one sub-pixel. The backlight module 2 is arranged on the backlight side of the display module 1. The light guide layer 3 is provided with a contact surface 31 and a back surface which are opposite to each other, the back surface is arranged opposite to the display module 1, and the contact surface 31 is used for being in contact with fingers. The first polarizer 6 is arranged on the light incident side of the liquid crystal layer 11; the second polarizer 7 is disposed on a side of the liquid crystal layer 11 opposite to the first polarizer 6.

The identification light source 4 is disposed toward the light guide layer 3, and is configured to emit light to the light guide layer 3, and at least a portion of the light entering the light guide layer 3 can be totally reflected between the back surface of the light guide layer 3 and the contact surface 31. The identification light induction circuit 5 is arranged on one side, back to the other side, of the first polaroid 6, of the second polaroid 7, the identification light induction circuit 5 is used for inducing light of the identification light source 4 and generating a fingerprint signal, and the identification light induction circuit 5 is of a transparent structure. At least part of the light reflected by the finger can penetrate through the color film layer 12 and the transparent area 111, and the light penetrating through the transparent area 111 can penetrate through the first polarizer 6 to reach the identification light sensing circuit 5, so as to form a fingerprint image on the identification light sensing circuit 5.

As shown in fig. 3, when performing fingerprint recognition, the lcd panel of the present disclosure may close the backlight module 2, emit light into the light guide layer 3 by the recognition light source 4, and control the recognition area of the liquid crystal layer 11 to form a plurality of light transmission areas 111; as shown in fig. 1, when a finger does not contact the area of the contact surface 31 corresponding to the identification area, the light in the light guide layer 3 is totally reflected at the contact surface 31 and the back surface; as shown in fig. 2, when a finger contacts a region of the contact surface 31 corresponding to the identification region, the total reflection condition of the contact region is destroyed, so that light can be emitted from the contact region to the finger and reflected by the finger, and since the reflection of the finger is diffuse reflection, when the light reflected by the finger irradiates the back surface of the light guide layer 3, the incident angle of at least part of the light does not satisfy the total reflection condition, so that the light can irradiate to the identification light sensing circuit 5 through the transparent region 111 and the first polarizer 6 after passing through the filter region 121 of the color film layer 12, and a fingerprint image is formed on the identification light sensing circuit 5 according to the pinhole imaging principle, so as to identify fingerprint information. The light passing through the liquid crystal layer 11 outside the light-transmitting region 111 cannot pass through the first polarizer 6, so that the light can be modulated by the liquid crystal layer 11 to realize pinhole imaging.

When displaying images, the backlight module 2 can be opened, the liquid crystal layer 11 can be controlled to be in a conventional display state, the light-transmitting area 111 is eliminated, the images are displayed by using the modulation of the liquid crystal layer 11 on light rays, and the identification light ray sensing circuit 5 cannot shield the light rays emitted by the backlight module 2. If the light emitted by the identification light source 4 is visible light, the identification light source 4 may not emit light to ensure the display effect, and if the light emitted by the identification light source 4 is invisible light, the identification light source 4 may not be turned off.

The following describes each part of the liquid crystal display panel according to the embodiment of the present disclosure in detail:

as shown in fig. 1-3, the display module 1 includes a liquid crystal layer 11 and a color film layer 12, the liquid crystal layer 11 can be used to adjust the polarization direction of light, so as to adjust the light transmittance of the first polarizer 6 and the second polarizer 7, and the specific principle is not described in detail herein. The liquid crystal layer 11 may form an identification region including a plurality of light-transmitting regions 111 corresponding to the sub-pixels, and each light-transmitting region 111 corresponds to one sub-pixel, and any sub-pixel corresponds to at most one light-transmitting region 111. The light penetrating through the light-transmitting area 111 can penetrate through the first polarizer 6, while the light penetrating through the area outside the light-transmitting area 111 cannot penetrate through the first polarizer 6, so that the light reflected by the finger can realize pinhole imaging on the identification light sensing circuit 5 by using each light-transmitting area 111. The manner of driving the liquid crystal layer 11 to form the light-transmitting region 111 is not particularly limited herein. In the display period, the identification region of the liquid crystal layer 11 of the identification region may be in a normal display state where the light transmission region 111 is absent so as to display an image, and the identification region may not perform fingerprint recognition.

It should be noted that the identification region is not a solid structure, but is a region obtained by differently controlling the liquid crystal molecules of the liquid crystal layer 11 corresponding to the transparent region 111 and the opaque region through the pixel electrode 15 and the common electrode 16 and by using the first polarizer 6 and the second polarizer 7, only the light of a part of the region corresponding to the transparent region 111 can pass through the first polarizer 6, and the light of the other regions cannot pass through the first polarizer 6, so that the occurrence and elimination of the identification region can be realized by controlling the liquid crystal layer 11 through the pixel electrode 15. Preferably, when only a part of the regions corresponding to the transparent region 111 transmits light and other regions do not transmit light, the liquid crystal layer 11 of the transparent region 111 corresponds to the maximum transmittance state of the liquid crystal display panel, that is, the light transmitted through the transparent region 111 can completely transmit the first polarizer 6 without being blocked by the first polarizer 6, and the liquid crystal layer 11 of the other regions of the identification region corresponds to the minimum transmittance state of the liquid crystal display panel, and the light transmitted through the transparent region 111 can be completely blocked by the first polarizer 6.

The color film layer 12 is located on the light emitting side or the light incident side of the liquid crystal layer 11, the color film layer 12 includes a plurality of filter regions 121 corresponding to the sub-pixels one by one, and the filter regions 121 can only transmit light with a specified wavelength, so as to limit the light emitting color of the sub-pixels. Meanwhile, the color film layer 12 further includes an opaque black matrix 122, and the black matrix 122 may separate a plurality of filter regions 121 on the color film layer 12, wherein the liquid crystal display panel has a plurality of pixels, each pixel includes a plurality of sub-pixels with the same number, and the color of each filter region 121 of each sub-pixel corresponding to the same pixel is different. For example: the four filter regions 121 corresponding to the four sub-pixels of the same pixel have red (R), green (G), blue (B) and white (W), respectively, and white is transparent to various visible lights.

The identification area may be a part of the liquid crystal layer 11, or may be in the same range as the liquid crystal layer 11. Any one of the light-transmitting regions 111 corresponds to one of the filter regions 121 within the identification region range, and each of the filter regions 121 corresponds to at most one of the light-transmitting regions 111, i.e., the filter regions 121 corresponding to different light-transmitting regions 111 are different. The color of the filter region 121 corresponding to each light-transmitting region 111 is the same; meanwhile, the light emitted by the identification light source 4 may be white light, a mixture of lights of different colors (e.g., a mixture of lights of three colors, red, green, and blue), or a light of the same color as the light filtering region 121 corresponding to each light transmitting region 111, so as to ensure that the light emitted by the identification light source 4 can pass through the color film layer 12 and pass through the light transmitting region 111. For example, the filter region 121 corresponding to each light-transmitting region 111 is fully transparent, and the sub-pixels corresponding to each light-transmitting region 111 are used for emitting white light. Certainly, the light emitted by the identification light source 4 may also be invisible light such as infrared light, and the light passing through the light transmission region 111 can pass through the first polarizer 6 under the control of the light transmission region 111, and forms an image on the identification light sensing circuit 5 to realize fingerprint identification, and correspondingly, the identification light sensing circuit 5 may adopt a sensing layer capable of sensing the invisible light.

At most one of any two adjacent filter regions 121 corresponds to one transparent region 111, so as to prevent the two transparent regions 111 from being too close to each other, thereby causing crosstalk in the fingerprint image. The orthographic projection of any light-transmitting region 111 in the identification region completely coincides with the corresponding filter region 121, that is, the shape and size of the cross section of any light-transmitting region 111 are the same as those of the filter region 121 corresponding to the light-transmitting region 111. The outline of the sub-pixel corresponding to the light-transmitting region 111 is square or circular, and the area of the sub-pixel is smaller than that of the sub-pixel not corresponding to the light-transmitting region 111.

In an embodiment, as shown in fig. 1 to fig. 3, the display module 1 includes an array substrate 13 and a color filter substrate 14, which are arranged in an opposite-box manner, the liquid crystal layer 11 is located between the array substrate 13 and the color filter substrate 14, the array substrate 13 includes a first substrate and a driving layer located on one side of the first substrate close to the liquid crystal layer 11, and the driving layer includes thin film transistors distributed in an array. The color film substrate 14 includes the color film layer 12 and the second substrate 141, and the color film layer 12 is stacked on one side of the second substrate 141 close to the liquid crystal layer 11.

In another embodiment, the display module further includes a first substrate and a second substrate disposed opposite to the cell, and the liquid crystal layer is disposed between the first substrate and the second substrate, wherein the first substrate includes an array substrate and the color film layer, and the color film layer is disposed between the array substrate and the liquid crystal layer.

For example, the number of the pixel electrodes 15 is plural, and the pixel electrodes 15 may be distributed between the liquid crystal layer 11 and the array substrate 13 in an array, the pixel electrodes 15 are disposed in one-to-one correspondence with the filter regions 121, and in one-to-one correspondence with the sub-pixels, that is, each of the light-transmitting regions 111 corresponds to one pixel electrode 15; meanwhile, the filter regions 121 and the pixel electrodes 15 having the corresponding relationship are identical in shape and size.

The common electrode 16 is disposed between the color film layer 12 and the liquid crystal layer 11, and the rotation direction of the liquid crystal layer 11 can be adjusted by the electric field between the pixel electrode 15 and the common electrode 16, so that the light transmission region 111 can be formed or eliminated, and the identification region can be in a state of having the light transmission region 111 or in a normal display state without the light transmission region 111. The size and shape of the cross section of the light transmission region 111 are defined by its corresponding pixel electrode 15.

The sub-pixel corresponding to the light-transmitting area 111 and the sub-pixel directly adjacent to the sub-pixel in the row or column direction are in the same color, and the area of the sub-pixel directly adjacent to the sub-pixel corresponding to the light-transmitting area 111 is larger than that of the sub-pixel not directly adjacent to the sub-pixel, so as to meet the requirement of pinhole imaging.

For example, as shown in fig. 1, any of the filter regions 121 corresponding to the light-transmitting regions 111 is smaller than any of the filter regions 121 not corresponding to the light-transmitting regions 111, for example, as shown in fig. 4, each of the filter regions 121 is rectangular, wherein the filter region 121a is a filter region corresponding to one of the light-transmitting regions 111, the

filter regions

121b and 121c around the filter region 121a do not correspond to the light-transmitting regions 111, and the

filter regions

121b and 121c are both larger than the filter region 121 a; meanwhile, in fig. 4, the two

filter regions

121b and 121a are located in the same row and located at two sides of the filter region 121a, and the size of the filter region 121b matches with that of the filter region 121a, so that the filter region 121b is enlarged due to the reduction of the filter region 121a, that is, larger than the filter region 121c in the row different from that of the filter region 121 a.

Meanwhile, any pixel electrode 15 corresponding to the light-transmitting region 111 is smaller than any pixel electrode 15 not corresponding to the light-transmitting region 111, so that the size of the light-transmitting region 111 is reduced.

As shown in fig. 3, the backlight module 2 is disposed on a backlight side of the display module 1, for example, a side of the array substrate 13 away from the color filter substrate 14. The backlight module 2 can emit light to the display module 1 so as to display images. The backlight module 2 may be of a side-in type structure, and certainly, the backlight module 2 may also be of a direct-out type structure, which is not limited herein.

As shown in fig. 1-3, the light guide layer 3 may be a flat plate structure made of a transparent material, and has a contact surface 31 and a back surface opposite to each other, the back surface is disposed opposite to the display module 1, and the contact surface 31 is located on a side of the back surface away from the display module 1 and is used for contacting with a finger.

The light guide layer 3 may further include a light incident surface 32 connecting the contact surface 31 and the back surface, and the light incident surface 32 may be a plane or a curved surface, which is not particularly limited herein.

As shown in fig. 1 and fig. 2, the identification light source 4 is disposed toward the light guide layer 3, for example, disposed opposite to the light incident surface 32 of the light guide layer 3, and can emit light toward the light incident surface 32, and the light emitting color of the identification light source 4 is the same as the color of the filter region 121 corresponding to the light transmission region 111, that is, the light emitting color of the sub-pixel corresponding to the light transmission region 111, so that the light emitted by the identification light source 4 can penetrate through the filter region 121 corresponding to the light transmission region 111. Certainly, the light emitted by the identification light source 4 may also be invisible light such as infrared light, and the light passing through the light transmission region 111 can pass through the first polarizer 6 under the control of the light transmission region 111, and forms an image on the identification light sensing circuit 5 to realize fingerprint identification, and correspondingly, the identification light sensing circuit 5 may adopt a sensing layer capable of sensing the invisible light.

Meanwhile, at least part of the light rays emitted by the identification light source 4 and entering the light guide layer 3 can be totally reflected between the back surface and the contact surface 31, and the light rays of the identification light source 4 can be prevented from being emitted from the contact surface 31 or the back surface under the condition that the total reflection condition is not damaged, for example, under the condition that media on two sides of the light guide layer 3 are not changed. In order to satisfy the total reflection condition, the contact surface 31 may be in contact with air, and the refractive index of the light guide layer 3 is greater than that of air; the refractive index of the display module 1 or other film layers contacting with the back surface of the light guide layer 3 is smaller than that of the light guide layer 3. As shown in fig. 2, when the user's finger contacts the contact surface 31, the air of the contact area a is discharged, the total reflection condition of the contact area a is broken, and thus the light may exit from the contact area a and be irradiated onto the finger.

As shown in fig. 1 and 2, the identification light sensing circuit 5 is disposed on a side of the first polarizer 6 opposite to the second polarizer 7, for example, between the first polarizer 6 and the backlight module 2. Each light-transmitting area 111 of the identification area corresponds to the identification light sensing circuit 5, i.e. the orthographic projection of the light-transmitting area 111 on the plane where the identification light sensing circuit 5 is located in the identification light sensing circuit 5. The recognition light sensing circuit 5 is a transparent structure, which can avoid shielding the light emitted from the backlight module 2, wherein the transparent structure is not limited to be completely transparent, or translucent, or partially transparent, but if the transparent structure is partially transparent, the range of the transparent region should meet the requirement of recognizing the fingerprint image, for example, the range of the transparent region is greater than 80% of the whole range of the recognition light sensing circuit 5, and the like, and is not specially limited herein.

It should be noted that, if the backlight module 2 is a side-in type backlight module and includes a light source and a light guide plate, the identification light sensing circuit 5 is only required to be located on a side of the first polarizer 6 opposite to the second polarizer 7, for example, between the light guide plate and the display module 1, and one or more optical films may be further disposed between the identification light sensing circuit 5 and the display module 1. If backlight unit 2 is straight following formula backlight unit, including the light source of a plurality of array distributions, discernment light induction circuit 5 only need between light source and display module assembly 1 can, still can set up one deck or multilayer optical film piece between discernment light induction circuit 5 and the display module assembly 1.

The identification light sensing circuit 5 may be an independent integrated circuit chip, or may be a circuit integrated in the display module 1, for example, integrated on the same circuit board as the pixel driving circuit of the array substrate of the display module 1, or the identification light sensing circuit 5 may be a circuit independent from the display module 1.

As shown in fig. 1 and 2, according to the principle of pinhole imaging, the light reflected by the finger and transmitted by the light-transmitting area 111 forms a fingerprint image on the identification light sensing circuit 5, and the identification light sensing circuit 5 can perform photoelectric conversion so as to obtain an electrical signal capable of reflecting fingerprint information according to the light reflected by the finger, and the specific sensing principle is not described in detail herein. For example, the identification light sensing circuit 5 may include a plurality of sensing units distributed in an array to respectively receive the light passing through each of the light transmitting regions 111 and passing through the first polarizer 6.

Since the recognition light sensing circuit 5 may cause loss of light, in order to improve the uniformity of the brightness of the liquid crystal display panel, therefore:

in one embodiment, the backlight module 2 is a side-in type backlight module, and includes a backlight source and a light guide plate 21, the light guide plate 21 has a light emitting surface and a backlight surface opposite to each other, the light emitting surface is disposed opposite to the display module 1, the backlight surface is located on a side of the light emitting surface away from the display module 1, and the backlight surface has a plurality of reflective dots.

As shown in fig. 6, the area of the backlight surface of the light guide plate 21 corresponding to the recognition light sensing circuit 5 is a first area S1, the density of the dots in the first area S1 is a first density, the area of the backlight surface corresponding to the area other than the recognition light sensing circuit 5 is a second area S2, and the density of the dots in the second area S2 is a second density. The first density may be made greater than the second density, thereby improving the brightness of the area of the light guide plate 21 corresponding to the recognition light sensing circuit 5, compensating for the loss caused by the recognition light sensing circuit 5, and improving the uniformity of the brightness of the liquid crystal display panel.

In another embodiment, as shown in fig. 7, the backlight module 2 is a direct-type backlight module, and includes a plurality of backlights 22 facing the display module 1, and at least a portion of the backlights 22 correspond to the light-identifying sensing circuit 5. The area facing the recognition light sensing circuit 5 is the first area S1, the backlight 22 in the first area S1 emits light with the first light emission intensity, the area facing the area outside the recognition light sensing circuit 5 is the second area S2, and the backlight 22 in the second area S2 emits light with the second light emission intensity. The product of the first luminous intensity and the light transmittance of the identification light sensing circuit 5 is equal to the second luminous intensity, so that the loss caused by the identification light sensing circuit 5 is compensated, and the uniformity of the brightness of the liquid crystal display panel is improved.

As shown in fig. 1 and fig. 2, in order to prevent the accuracy of identification from being improved, the ranges of the reflected light of the finger received by the two adjacent light-transmitting areas 111 on the contact surface 31 may be at least partially overlapped, so that the identification light sensing circuit 5 may receive the light reflected by each area of the finger, and the missing of scanning the fingerprint is avoided. Meanwhile, the light rays penetrating through the two adjacent light transmission areas 111 are spaced from each other in the range of the identification light ray sensing circuit 5, namely, the light rays penetrating through the two adjacent light transmission areas 111 are not overlapped in the irradiation range of the identification light ray sensing circuit 5 on the surface close to the color film layer 12, so that the fingerprint information is prevented from being interfered, and the accuracy of fingerprint identification is ensured.

Further, the area of the range of the finger reflected light received by any one of the light-transmitting areas 111 on the contact surface 31 is larger than the area of the range of the light transmitted by the light-transmitting area 111 on the identification light sensing circuit 5, i.e., S > L in fig. 1 and 2.

The ratio of the distance between the contact surface 31 of the light guide layer 3 and the middle cross section of the light transmission region 111 to the distance between the identification light sensing circuit 5 and the middle cross section of the light transmission region 111 is not less than

The middle cross section of the light-transmitting region 111 is a cross section having an equal distance from both ends of the light-transmitting region 111.

As shown in fig. 1 to 3, the first polarizer 6 is disposed on the light incident side of the liquid crystal layer 11, for example, between the identification light sensing circuit 5 and the display module 1, and the second polarizer 7 is disposed on the opposite side of the liquid crystal layer 11 from the first polarizer 6, for example, between the display module 1 and the light guide layer 3. The first polarizer 6 is used for converting the light beam generated by the backlight module 2 into polarized light, and the second polarizer 7 is used for analyzing the polarized light modulated by the liquid crystal layer 11 so as to display images and form an identification area. During fingerprint identification, the light that discernment light source 4 sent, after finger reflection, can loop through second polaroid 7, the printing opacity district 111 and the first polaroid 6 of liquid crystal layer 11, finally reach discernment light induction circuit 5, form the fingerprint image, at this in-process, the region outside printing opacity district 111 and the printing opacity district 111 of liquid crystal layer 11 can make the light that the finger was reflected be in different polarization states, and the light that sees through printing opacity district 111 just can pass through first polaroid 6, form the fingerprint image according to aperture formation of image principle, and the light that sees through the region outside printing opacity district 111 then can not see through first polaroid 6, avoid causing the influence to the fingerprint image.

The lcd panel of the present disclosure may further include a touch module 8 disposed on one side of the light guide layer 3 facing the display module 1, for example, between the light guide layer 3 and the second polarizer 7, for determining a touch position of a finger, and controlling the recognition light sensing circuit 5 to generate a fingerprint signal according to the received recognition light when the touch position corresponds to a region of the recognition light sensing circuit 5. The touch module 8 may include a first touch electrode, an insulating layer, and a second touch electrode stacked in sequence, and the specific structure is not particularly limited.

The embodiment of the present disclosure further provides a driving method of a liquid crystal display panel, which is used for the liquid crystal display panel of the above embodiment, and the driving method includes:

in the fingerprint identification period:

emitting light rays to the light incident surface, and at least closing a light source of the backlight module corresponding to the identification area;

in the display period:

opening the backlight module;

In the driving method of the embodiment of the present disclosure, as shown in fig. 1 and fig. 2, during the fingerprint identification period, at least the light source corresponding to the identification area in the backlight module 2 does not emit light, but the identification light source 4 emits light, and the light reflected by the finger and transmitted by the light transmission area 111 of the liquid crystal layer 11 can penetrate through the first polarizer 6 and reach the identification light sensing circuit 5, at this time, the liquid crystal display panel does not display an image, but is only used for fingerprint identification; as shown in fig. 3, in the display period, the backlight module 2 emits light, and the liquid crystal layer 11 does not have the light-transmitting region 111, at this time, the liquid crystal display panel can display an image without performing fingerprint identification, wherein if the light emitted by the identification light source 4 is visible light, the identification light source 4 is not emitted to ensure the display effect, and if the light emitted by the identification light source 4 is invisible light, the identification light source 4 is not turned off. Thus, fingerprint recognition can be realized on the liquid crystal display panel.

For the liquid crystal display panel having the touch module 8, the structure and the position of the touch module 8 may refer to the touch module 8 in the above, which is not described herein again, and based on this, the driving method further includes:

Moreover, although the steps of the methods of the present disclosure are depicted in the drawings in a particular order, this does not require or imply that the steps must be performed in this particular order, or that all of the depicted steps must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc.

The disclosed embodiment also provides a display device, which can be used for a mobile phone, a tablet computer or other terminal equipment, which is not listed here. Meanwhile, the display device comprises the liquid crystal display panel of the above embodiment, and the structure of the liquid crystal display panel and the beneficial effects of the display device are not described in detail herein.

In addition, as shown in fig. 5, the display module 1 is provided with a mounting hole 101 penetrating through the display module 1, and the mounting hole 101 may extend in a direction perpendicular to the contact surface 31. The recognition light source 4 is located in the mounting hole 101, and the camera module 100 can be arranged in the mounting hole 101. And the orthographic projections of the identification light source 4 and the camera module 100 on the contact surface 31 are not overlapped, so that the identification light source 4 is prevented from blocking the camera module 100 to shoot images. Therefore, the space for placing the camera module 100 can be utilized to place the identification light source 4, and the space is saved.

The shape of the installation hole 101 may be circular, rectangular or other closed shapes, or the installation hole 101 may also be opened at the edge of the light guide layer 3, and its cross section may be in an unclosed shape such as U-shape, semicircular shape, etc. The identification light source 4 may emit light toward the light guide layer 3.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A liquid crystal display panel comprising a plurality of sub-pixels, wherein the liquid crystal display panel comprises:

A display module includes a liquid crystal layer and a color filter layer on one side of the liquid crystal layer, the color filter layer includes a plurality of filter regions corresponding to the sub-pixels one-to-one, and the liquid crystal layer is used to form an identification area, the identification area includes a plurality of light-transmitting areas corresponding to the sub-pixels;

a backlight module, located on the backlight side of the display module;

a first polarizer, arranged on the light incident side of the liquid crystal layer;

a second polarizer, disposed on the side of the liquid crystal layer opposite to the first polarizer;

The light guide layer has a contact surface and a back surface opposite to each other, the back surface is arranged opposite to the display module, and the contact surface is used for contact with fingers;

Identifying a light source for emitting light to the light guide layer, and at least part of the light entering the light guide layer can be totally reflected between the back surface and the contact surface;

An identification light sensing circuit, which is arranged on the side of the first polarizer opposite to the second polarizer, is used to sense the light of the identification light source and generate a fingerprint signal, and the identification light sensing circuit is a transparent structure ;

After at least part of the light emitted by the identification light source is reflected by the finger, it can reach the identification light sensing circuit through the color filter layer, the light-transmitting area and the first polarizer, so as to sense the identification light in the identification light. A fingerprint image is formed on the circuit;

The sub-pixel corresponding to the light-transmitting area is of the same color as the sub-pixel directly adjacent to it in the row or column direction, and the sub-pixel directly adjacent to the sub-pixel corresponding to the light-transmitting area is of the same color. The area of the sub-pixels is larger than the area of the sub-pixels that are not directly adjacent.

2 . The liquid crystal display panel according to claim 1 , wherein the outline of the sub-pixel corresponding to the light-transmitting area is a square or a circle, and the area is smaller than that of the sub-pixel not corresponding to the light-transmitting area. 3 . The area of the sub-pixel.

3 . The liquid crystal display panel according to claim 1 , wherein the sub-pixels corresponding to the light-transmitting regions are used for emitting white light. 4 .

4 . The liquid crystal display panel according to claim 1 , wherein the corresponding ranges of the finger-reflected light received by the two adjacent light-transmitting regions on the contact surface at least partially overlap; The ranges of the light transmitted through the light-transmitting area on the identifying light-sensing circuit are not overlapped.

5 . The liquid crystal display panel according to claim 1 , wherein the range of the identification area is the same as the range of the liquid crystal layer, and each of the light-transmitting areas is evenly distributed in the identification area, and the identification area The projection of the light sensing circuit on the liquid crystal layer is directly opposite to the identification area.

6. The liquid crystal display panel according to claim 1, wherein the backlight module is a direct type backlight module or an edge type backlight module;

If the backlight module is a direct type backlight module, the backlight module includes a plurality of backlight sources facing the display module, and at least some of the backlight sources correspond to the identification area; correspond to the identification area The backlight source emits light with the first luminous intensity, and the backlight source corresponding to the area outside the identification area emits light with the second luminous intensity; the product of the first luminous intensity and the light transmittance of the identification light sensing circuit is equal to the the second luminous intensity;

If the backlight module is an edge-type backlight module, the backlight module includes a light guide plate, the light guide plate has a light emitting surface and a backlight surface opposite to each other, the light emitting surface faces the display module, and the The backlit surface has reflective dots; the density of the dots in the area corresponding to the recognition area on the backlit surface is the first density, and the density of the dots on the backlit surface corresponding to the area outside the recognition area is the second density density; the first density is greater than the second density.

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

The touch module is arranged between the light guide layer and the display module, and is used for judging the touch position of the finger, so as to control the recognition when the touch position is located in the recognition area The light sensing circuit generates a fingerprint signal according to the received light.

8. A method for driving a liquid crystal display panel, used in the liquid crystal display panel according to any one of claims 1-6, characterized in that, comprising:

During the fingerprint identification period:

emit light to the light guide layer, and at least turn off the light source of the backlight module corresponding to the identification area;

During the display period:

turn on the backlight module;

The identification area of the liquid crystal layer is controlled to be in a normal display state.

9. The driving method according to claim 8, wherein the liquid crystal display panel further comprises:

a touch module, disposed on the side of the light guide layer facing the backlight module;

The driving method further includes:

The touch position of the finger is determined, and when the touch position is located in the recognition area, the fingerprint recognition period is entered.

10. A display device, comprising the liquid crystal display panel according to any one of claims 1-7.

11 . The display device according to claim 10 , wherein the display module is provided with an installation hole penetrating in a direction perpendicular to the contact surface, and the identification light source is arranged in the installation hole; 11 .

The display device also includes:

The camera module is arranged in the installation hole.