CN111240062A

CN111240062A - Liquid crystal display screen integrating fingerprint identification function and electronic device

Info

Publication number: CN111240062A
Application number: CN202010201913.5A
Authority: CN
Inventors: 吴安平; 吴雨桐
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2020-06-05
Anticipated expiration: 2040-03-20
Also published as: CN111240062B

Abstract

The application discloses liquid crystal display of integrated fingerprint identification function, including filter layer, liquid crystal layer, pixel electrode layer, TFT drive layer, backlight unit and image sensor layer. The filter layer comprises a plurality of filters, the liquid crystal layer comprises a plurality of liquid crystal units, the pixel electrode layer comprises a plurality of pixel electrodes, and the pixel electrodes correspond to the liquid crystal units and the filters one to one. The TFT driving layer is used for applying a driving voltage to at least part of the pixel electrodes so as to drive at least part of the corresponding liquid crystal units to be in an opening state. The backlight unit is used for emitting emergent light, and the emergent light reaches the light-emitting surface side of the liquid crystal display screen after passing through at least part of the liquid crystal unit in the opening state and the corresponding optical filter. The light sensor of the image sensor layer receives the reflected light reflected by the finger and converts the reflected light into a photoelectric signal for generating a fingerprint image. The application also provides an electronic device. The application makes the integration of the fingerprint identification function of the liquid crystal display screen possible.

Description

Liquid crystal display screen integrating fingerprint identification function and electronic device

Technical Field

The invention relates to the field of display, in particular to a liquid crystal display screen integrated with a fingerprint identification function and an electronic device with the liquid crystal display screen.

Background

At present, in consideration of the requirement of unlocking the front fingerprint of a user, most of electronic devices such as mobile phones and the like place a fingerprint identification area on the front of the device, so that the display area of a display screen can be compressed, and the screen occupation ratio is influenced. Particularly, for a terminal equipped with an LCD (Liquid Crystal Display) screen, since the LCD screen and the fingerprint identification area are two independent functional modules, there is a difference in the functional implementation manners, and it is impossible to place the fingerprint identification device below the LCD screen to implement the lower fingerprint of the LCD screen. Therefore, in the prior art, for an electronic device equipped with an LCD screen, a front fingerprint identification area is set in a non-display area outside the LCD screen, and the front fingerprint identification area needs to be additionally reserved in the non-display area, and occupies a part of a front display area of the device, which is not in line with technical requirements of current users and industries on high screen occupation and full screen terminals.

Disclosure of Invention

The embodiment of the application provides a liquid crystal display screen and an electronic device integrating a fingerprint identification function, so as to solve the problems.

In one aspect, a liquid crystal display screen integrated with a fingerprint identification function is provided, and the liquid crystal display screen comprises a filter layer, a liquid crystal layer, a pixel electrode layer, a TFT (thin film transistor) driving layer, a backlight unit and an image sensor layer. The filter layer includes filters arranged in an array. The liquid crystal layer comprises a plurality of liquid crystal units which are arranged in an array. The pixel electrode layer comprises a plurality of pixel electrodes which are arranged in an array mode, wherein the pixel electrodes correspond to the liquid crystal units and the optical filters one to one. The TFT driving layer is used for applying a driving voltage to at least part of the pixel electrodes so as to drive at least part of the corresponding liquid crystal units to be in an opening state. The backlight unit is used for emitting emergent light towards the light emitting surface side of the liquid crystal display screen, and when the TFT driving layer applies driving voltage to at least part of the pixel electrodes to drive at least part of the liquid crystal units to be in an open state, the emergent light reaches the light emitting surface side of the liquid crystal display screen after passing through at least part of the liquid crystal units in the open state and the corresponding optical filters. The image sensor layer comprises a plurality of light sensors which are arranged in an array, the light sensors are used for receiving reflected light rays of the emergent light rays reflected by a shielding object, the shielding object is positioned on the light emitting surface side of the liquid crystal display screen and comprises a finger, and the light sensors convert the reflected light rays into photoelectric signals so as to generate images including fingerprint images.

In another aspect, an electronic device is provided, which includes a liquid crystal display including a filter layer, a liquid crystal layer, a pixel electrode layer, a TFT driving layer, a backlight unit, and an image sensor layer. The filter layer includes filters arranged in an array. The liquid crystal layer comprises a plurality of liquid crystal units which are arranged in an array. The pixel electrode layer comprises a plurality of pixel electrodes which are arranged in an array mode, wherein the pixel electrodes correspond to the liquid crystal units and the optical filters one to one. The TFT driving layer is used for applying a driving voltage to at least part of the pixel electrodes so as to drive at least part of the corresponding liquid crystal units to be in an opening state. The backlight unit is used for emitting emergent light towards the light emitting surface side of the liquid crystal display screen, and when the TFT driving layer applies driving voltage to at least part of the pixel electrodes to drive at least part of the liquid crystal units to be in an open state, the emergent light reaches the light emitting surface side of the liquid crystal display screen after passing through at least part of the liquid crystal units in the open state and the corresponding optical filters. The image sensor layer comprises a plurality of light sensors which are arranged in an array, the light sensors are used for receiving the reflected light which is reflected by the shielding object including the finger on the light-emitting surface side of the liquid crystal display screen and reflected by the shielding object, and the light sensors convert the reflected light into photoelectric signals so as to generate images including fingerprint images.

This application is through increasing the image sensor layer in liquid crystal display to liquid crystal unit through control liquid crystal display is in the open mode and makes light can pass in and out liquid crystal display, and realizes optical fingerprint function under the screen, makes the integrated fingerprint identification function of liquid crystal display become for the possibility.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a block diagram of an electronic device according to an embodiment of the present application.

Fig. 2 is a schematic diagram of a stacked structure of a liquid crystal display integrated with a fingerprint identification function in an embodiment of the present application.

Fig. 3 is a schematic plan view of a filter layer according to an embodiment of the present disclosure.

Fig. 4 is a schematic plan view of a liquid crystal layer in an embodiment of the present application.

Fig. 5 is a schematic plan view illustrating a TFT driving layer and a pixel electrode layer in one embodiment of the present application.

Fig. 6 is a schematic diagram illustrating a positional relationship between partial layers of a liquid crystal display panel according to an embodiment of the present application.

Fig. 7 is a schematic plan view of an image sensor layer in an embodiment of the present application.

Fig. 8 is a schematic plan view of a backlight unit in an embodiment of the present application.

Fig. 9 is a schematic view of a backlight unit in an embodiment of the present application, taken along the section line I-I in fig. 8.

Fig. 10 is a schematic plan view of a backlight unit in another embodiment of the present application.

Fig. 11 is a schematic view of a backlight unit in another embodiment of the present application, taken along the section line II-II in the figure.

Fig. 12 is a schematic view of a backlight unit in another embodiment of the present application, taken along the section line III-III in fig. 10.

FIG. 13 is another schematic view of a backlight unit in another embodiment of the present application, taken along section line II-II in FIG. 10.

Fig. 14 is a schematic optical path diagram of fingerprint image imaging performed by finger touching or pressing the liquid crystal display screen in an embodiment of the present application.

FIG. 15 is a schematic plan view of an image sensor layer in another embodiment of the present application.

Fig. 16 is a schematic view of a laminated structure of a liquid crystal display panel in another embodiment of the present application.

Fig. 17 is a schematic diagram illustrating photoelectric signals generated by three photo-sensors according to an embodiment of the present application.

Fig. 18 is a specific circuit diagram of a driving unit in a TFT driving layer according to an embodiment of the present application.

Fig. 19 is a schematic view of a partial structure of the TFT driving layer in another embodiment of the present application.

Fig. 20 is a specific circuit diagram of the connection between the enabling unit and the photo sensor according to an embodiment of the present application.

Fig. 21 is a schematic view of an electronic device according to an embodiment of the present application.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 and fig. 2 together, fig. 1 is a block diagram of an electronic device 100 according to an embodiment of the present disclosure, and fig. 2 is a schematic diagram of a stacked structure of a liquid crystal display 10 (hereinafter referred to as a liquid crystal display 10) integrated with a fingerprint identification function according to an embodiment of the present disclosure. The electronic device includes the liquid crystal display 10.

The liquid crystal display panel 10 includes a filter layer 11, a liquid crystal layer 12, a pixel electrode layer 13, a TFT driving layer 14, a backlight unit 15, and an image sensor layer 16.

Referring to fig. 3-7, the filter layer 11 includes filters 111 arranged in an array. The liquid crystal layer 12 includes a plurality of liquid crystal cells 121 arranged in an array. The pixel electrode layer 13 includes a plurality of pixel electrodes 131 arranged in an array, wherein the pixel electrodes 131 correspond to the liquid crystal units 121 and the optical filters 111 one to one. The TFT driving layer 14 is used for applying a driving voltage to at least a portion of the pixel electrode 131 to drive at least a portion of the corresponding liquid crystal cell 121 to be in an on state. The backlight unit 15 is configured to emit an outgoing light toward the light emitting surface side of the liquid crystal display panel, and when the TFT driving layer 14 applies a driving voltage to at least a part of the pixel electrodes 131 to drive at least a part of the liquid crystal cells 121 to be in an on state, the outgoing light passes through the liquid crystal cells 121 in the on state and the corresponding filters 111 and reaches the light emitting surface side of the liquid crystal display panel 10. The image sensor layer 16 includes a plurality of photo sensors 161 arranged in an array, the photo sensors 161 are configured to receive the reflected light of the outgoing light reflected by a barrier, the barrier is a barrier located on the light-emitting side of the liquid crystal display 10 and includes a finger, and the photo sensors 161 convert the reflected light into an electro-optical signal for generating an image including a fingerprint image.

Therefore, in the present application, by adding the image sensor layer 16 to the liquid crystal display 10 and controlling the liquid crystal unit 121 of the liquid crystal display 10 to be in the on state, light can enter and exit the liquid crystal display 10, so as to realize the optical fingerprint function under the liquid crystal display 10, and the integration of the fingerprint recognition function into the liquid crystal display 10 becomes possible.

Wherein, the object is a finger-containing object located on the light-emitting surface side of the liquid crystal display panel 10, and the object means: the shield is located on the light exit side of the lcd panel 10 and may include a finger or the like. When the object is a finger, the light sensor 161 converts the reflected light into a photoelectric signal, and the photoelectric signal is used to generate a fingerprint image.

As shown in fig. 2, the liquid crystal layer 12 is located between the filter layer 11 and the pixel electrode layer 13, the TFT driving layer 14 is located between the pixel electrode layer 13 and the backlight unit 15, the image sensor layer 16 is located between the pixel electrode layer 13 and the TFT driving layer 14 or between the liquid crystal layer 12 and the pixel electrode layer 13, the filter layer 11 is close to the light-emitting surface side of the liquid crystal display screen 10, and the backlight unit 15 is far away from the light-emitting surface side of the liquid crystal display screen 10.

That is, the image sensor layer 16 may be located between the liquid crystal layer 12 and the TFT driving layer 14, and further, the image sensor layer 16 and the pixel electrode layer 13 may be located between the liquid crystal layer 12 and the TFT driving layer 14, and the positions of the image sensor layer 16 and the pixel electrode layer 13 may be switched. For example, as shown in fig. 2, the image sensor layer 16 is located between the pixel electrode layer 13 and the TFT driving layer 14.

The light emitting surface side of the liquid crystal display panel 1 is located on the light emitting surface/display surface of the liquid crystal display panel 10 for displaying content for a user to view, and may also be understood as the front surface of the liquid crystal display panel 10.

In the application, "a" is located between "B" and "C", which means that "a" is located in a space between "B" and "C", but it is not excluded that other components or other layer structures are included between "B" and "C".

As shown in fig. 2, the liquid crystal display panel 10 further includes a common electrode layer 17, the common electrode layer 17 is located between the filter layer 11 and the liquid crystal molecule layer 12, the common electrode layer 17 is configured to provide a common zero potential, when the TFT driving layer 14 applies a driving voltage to at least a part of the pixel electrodes 131, an electric field is formed between the at least a part of the pixel electrodes 131 and the common electrode layer 17, and at least a part of the liquid crystal molecules in the corresponding liquid crystal cells 121 are driven to rotate and be in an on state.

When an electric field is formed between at least part of the pixel electrodes 131 and the common electrode layer 17, the liquid crystal cells 121 corresponding to at least part of the pixel electrodes 131 are in the electric field, so that the liquid crystal molecules in the liquid crystal cells 121 rotate to the same direction to form an optical path channel through which light can pass, and at this time, the liquid crystal cells 121 are in an on state.

The common electrode layer 17 may be a transparent ITO (indium tin oxide) plate, and is connected to a common ground of the electronic device 100 and is at a zero potential.

The pixel electrodes 131 arranged in an array may also be made of transparent ITO.

As shown in fig. 3, the plurality of filters 111 arranged in an array includes a plurality of filter sets 112, each filter set 112 includes a red filter R1, a green filter G1, and a blue filter B1, the red filter R1, the green filter G1, and the blue filter B1 respectively correspond to a red sub-pixel, a green sub-pixel, and a blue sub-pixel of the liquid crystal display panel 10, and each filter set 112 corresponds to a pixel unit P1 formed by the red sub-pixel, the green sub-pixel, and the blue sub-pixel.

The pixel unit is a unit that constitutes a pixel point in a display screen when the liquid crystal display screen 10 displays, and the pixel point can display multiple colors by performing three-primary color mixing through the red sub-pixel, the green sub-pixel and the blue sub-pixel, thereby realizing color display of the liquid crystal display screen 10.

As shown in fig. 4, the liquid crystal layer 12 includes a plurality of liquid crystal cells 121 arranged in an array, and each liquid crystal cell 121 corresponds to a sub-pixel. That is, each liquid crystal unit 121 is located below one of the filters 111 and corresponds to one of the red sub-pixel, the green sub-pixel, or the blue sub-pixel in a direction from the light emitting surface of the lcd panel 10 to the bottom. Wherein, the structure of each liquid crystal unit 121 is the same.

Fig. 5 is a schematic plan view illustrating the TFT driving layer 14 and the pixel electrode layer 13 at the same time, and the TFT driving layer 14 and the pixel electrode layer 13 are electrically connected, so that they are shown in the same view.

As mentioned above, the pixel electrode layer 13 includes a plurality of pixel electrodes 131 arranged in an array. Each pixel electrode 131 also corresponds to a sub-pixel. That is, each pixel electrode 131 is located below one liquid crystal unit 121 and corresponds to one of the red sub-pixel, the green sub-pixel, and the blue sub-pixel in a direction from the light emitting surface of the lcd panel 10 to the bottom. The structure of each pixel electrode 131 is also the same.

As shown in fig. 6, the pixel electrodes 131, the liquid crystal cells 121 and the filters 111 are equal in number and are in one-to-one correspondence in position, that is, the projections of each pixel electrode 131, the corresponding liquid crystal cell 121 and the corresponding filter 111 on the light exit surface are located in the same region, that is, in the same sub-pixel region.

Herein, the sub-pixels such as the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the pixel unit P1 refer to corresponding sub-pixel points or pixel point regions constituting the screen display when the liquid crystal display panel 10 displays the screen, and the optical filter 111, the liquid crystal unit 121, and the pixel electrode 131 in the direction from the light emitting surface to the back surface of the liquid crystal display panel 10 are all located in the corresponding sub-pixel regions.

When the TFT driving layer 14 applies a driving voltage to a certain pixel electrode 131, an electric field is formed between the pixel electrode 131 and the common electrode layer 17, and the corresponding liquid crystal cell 121, that is, the liquid crystal cell 121 located in the same sub-pixel region, is in the electric field, so that liquid crystal molecules in the liquid crystal cell 121 rotate under the action of the electric field to form an optical path through which light can pass, and at this time, the liquid crystal cells 121 are in an on state.

The backlight unit 15 is further configured to generate a backlight for display, and when a certain liquid crystal cell 121 is in an on state, the backlight is emitted through the turned-on liquid crystal cell 121, and is filtered by the corresponding filter 111 to show a corresponding color. Each pixel unit P1 becomes a pixel point showing corresponding color by color mixing of the sub-pixels, and the pixel points corresponding to the pixel units P1 show respective colors and can be combined into a complete display picture.

For example, for a pixel P1/pixel, when only the driving voltage is applied to the pixel electrode 131 corresponding to the red sub-pixel, only the liquid crystal cell 121 corresponding to the red sub-pixel is turned on to allow light to pass through, and the liquid crystal cells 121 corresponding to the green and blue sub-pixels are turned off to prevent light from passing through. At this time, the backlight is filtered by the red filter R1 corresponding to the red sub-pixel to be red, and the green sub-pixel and the blue sub-pixel do not display colors, so that the pixel unit P1/pixel is red as a whole. When the driving voltage is applied to the pixel electrode 131 corresponding to the red subpixel point and the green subpixel point, the liquid crystal cell 121 corresponding to the red subpixel point and the green subpixel point is in an on state to allow the light to pass, and the liquid crystal cell 121 corresponding to the blue subpixel point is in an off state to prevent the light from passing. At this time, the backlight is filtered by the red filter R1 corresponding to the red sub-pixel point to show red, and is filtered by the green filter G1 corresponding to the green sub-pixel point to show green, while the blue sub-pixel point does not display color, so that the pixel unit P1/pixel point integrally shows a mixed color of red and green, that is, yellow.

As shown in fig. 7, the image sensor layer 16 includes a plurality of photo sensors 161 arranged in an array. The number of the photo sensors 161 may be less than or equal to the number of all the sub-pixels of the liquid crystal display panel 10. For example, one photo sensor 161 may be disposed in each area corresponding to a sub-pixel, or one photo sensor 161 may be disposed every several sub-pixels. Wherein the size of the photo sensor 161 is smaller than the size of the area of the sub-pixel.

In an embodiment, the emergent light emitted by the backlight unit 15 includes invisible emergent light, as shown in fig. 7, the photo sensors 161 included in the image sensor layer 16 are invisible light sensors 162, that is, the image sensor layer 16 includes a plurality of invisible light sensors 162 arranged in an array.

The invisible light sensors 162 are configured to receive the invisible emergent light reflected by a blocking object, that is, a blocking object including a finger, located on the light emitting surface side of the liquid crystal display, and convert the invisible emergent light into a photoelectric signal for generating an image including a fingerprint image.

The invisible light may be infrared light, and the invisible light sensor 162 may be an infrared light sensor, such as a photodiode sensitive to infrared light.

The number of the invisible light sensors 162 may be equal to or less than the number of all the sub-pixels of the liquid crystal display panel 10, wherein the size of the invisible light sensors 162 is smaller than the size of the area of the sub-pixels, and each invisible light sensor 162 is disposed in the area of a corresponding sub-pixel.

For example, as shown in fig. 6, the number of the invisible light sensors 162 is equal to the number of all the sub-pixels of the lcd panel 10, and the number of the invisible light sensors 162 is equal to the number of the pixel electrodes 131, the liquid crystal units 121, and the filters 111, and the positions of the invisible light sensors 162 and the corresponding pixel electrodes, the corresponding liquid crystal units 121, and the corresponding filters 111 are in one-to-one correspondence, that is, the projections of the invisible light sensors 162 and the corresponding pixel electrodes, the corresponding liquid crystal units 121, and the corresponding filters 111 on the light emitting surface are located in the same area, that is, in the same.

For another example, the number of the invisible light sensors 162 is smaller than the number of all the sub-pixels of the liquid crystal display panel 10, the invisible light sensors 162 may be disposed only in the regions corresponding to some of the sub-pixels, and specifically, the invisible light sensors 162 may be disposed only in the positions corresponding to any one of the sub-pixel regions in each pixel unit P1. That is, only one invisible light sensor 162 is correspondingly disposed in the area of each pixel unit P1, and the invisible light sensor 162 may be disposed at a position corresponding to the red sub-pixel area, or at a position corresponding to the green sub-pixel area, or at a position corresponding to the blue sub-pixel area. Moreover, the sub-pixel regions corresponding to the invisible light sensors 162 in different pixel units P1 may be the same or different, for example, the invisible light sensor 162 in one pixel unit P1 may be disposed at a position corresponding to the red sub-pixel region, and the invisible light sensor 162 in another pixel unit P2 may be disposed at a position corresponding to the green sub-pixel region.

Since the area where the user's finger touches the liquid crystal display 10 often corresponds to a plurality of pixel units P1/pixel points, only one invisible light sensor 162 is correspondingly disposed in the area of each pixel unit P1, and more invisible light sensors 162 receive reflected light to perform photoelectric conversion, which can also meet the accuracy requirement of the fingerprint image.

In some embodiments, one invisible light sensor 162 may be disposed at intervals of a plurality of pixel cells P1, for example, one invisible light sensor 162 may be disposed at intervals of three, four, etc. pixel cells P1. Similarly, since the area where the user's finger touches the liquid crystal display 10 often corresponds to a plurality of pixel units P1/pixel points, the invisible light sensor 162 is disposed at an interval of a plurality of pixel units P1, and more invisible light sensors 162 receive reflected light to perform photoelectric conversion, which can also meet the accuracy requirement of the fingerprint image

The size of the invisible light sensor 162 is significantly smaller than the size of the area of the sub-pixel, for example, the size of the invisible light sensor 162 is 1/4, 1/5, etc. of the area of the sub-pixel, so that the outgoing light rays emitted from the backlight unit 15, the backlight, etc. are not affected too much, and the display performance is not greatly affected.

Fig. 8 is a schematic plan view of the backlight unit 15. As shown in fig. 8, the backlight unit 15 includes a light guide plate 151 and a plurality of non-visible lamps 152, the plurality of non-visible lamps 152 are arranged at least one side end of the light guide plate 151 at intervals, the plurality of non-visible lamps 152 are used for emitting invisible light, and the light guide plate 151 is used for transmitting the invisible light toward the light emitting surface side of the liquid crystal display panel 10 to form the invisible emergent light.

The invisible light is infrared light, and the invisible light 152 may be an infrared light emitting lamp or an infrared light emitter, and the like.

As shown in fig. 8, the light guide plate 151 is a square plate, and the side ends of the light guide plate 151 refer to four edge ends of two surfaces of the light guide plate 151 parallel to the light emitting surface of the liquid crystal display panel 10.

The backlight unit 15 further includes a plurality of visible light lamps 153, the plurality of visible light lamps 153 are arranged at least one side end of the light guide plate 151 at intervals, the plurality of visible light lamps 153 are configured to emit visible light, and the light guide plate 151 is configured to transmit the visible light toward a direction of a light emitting surface side of the liquid crystal display panel 10 to form a display backlight.

That is, in the present embodiment, the backlight unit 15 performs the fingerprint recognition function by emitting invisible outgoing light, and the display backlight performs the same function as the conventional backlight by emitting visible light, and both the invisible light and the visible light are transmitted to the light emitting surface side of the liquid crystal display panel 10 through the same light guide plate 151.

In some embodiments, the number of non-visible light lamps 152 and the number of visible light lamps 153 are disposed at the same lateral end of the light guide plate 151, and the number of non-visible light lamps 152 and the number of visible light lamps 153 are arranged in a doped manner.

As shown in fig. 8, the invisible light lamps 152 and the visible light lamps 153 are disposed at one side end of the light guide plate 151 and are spaced and doped along a long side of the side end. Specifically, the backlight unit 151 further includes a light source plate F1, and the invisible light lamps 152 and the visible light lamps 153 are first disposed on the light source plate F1 and then fixed to one side end of the light guide plate 151 through a light source plate F1.

In some embodiments, as shown in fig. 8, the number of the plurality of non-visible light lamps 152 is less than the number of the plurality of visible light lamps 153, and the doping arrangement of the plurality of non-visible light lamps 152 and the plurality of visible light lamps 153 is to make the plurality of visible light lamps 153 form a plurality of groups of visible light lamps 153 by using the plurality of visible light lamps 153 as a group, and then the plurality of groups of visible light lamps and the plurality of non-visible light lamps 152 are alternately arranged in sequence. Specifically, as shown in fig. 8, one invisible light lamp 152 is doped every a plurality of visible light lamps 153 on the light source board F1. Therefore, the influence on the brightness of the display backlight can be avoided as much as possible.

Fig. 9 is a schematic diagram of the backlight unit 15 in an embodiment, taken along the section line I-I in fig. 8, showing a more specific structure of the backlight unit 15.

As shown in fig. 9, the invisible light lamps 152 and the visible light lamps 153 are disposed on a side surface S1 of one side end of the light guide plate 151, wherein the side end is disposed on the side end of the light guide plate 151. The side surface S1 is a peripheral sidewall of the light guide plate 151, that is, the invisible light lamps 152 and the visible light lamps 153 are disposed at an edge of the light guide plate 151 and specifically disposed on the peripheral sidewall of the light guide plate 151.

As shown in fig. 9, the light guide plate 151 includes an upper surface 1511 and a lower surface 1512 parallel to the light emitting surface of the liquid crystal display panel 10, and the side surface S1 is a peripheral sidewall connected to the upper surface 1511 and the lower surface 1512.

Further, the invisible light lamps 152 and the visible light lamps 153 are first disposed on the light source plate F1, and then the light source plates F1 on which the invisible light lamps 152 and the visible light lamps 153 are disposed are attached to the side surface S1 of the light guide plate 151. The invisible light lamps 152 and the visible light lamps 153 respectively emit invisible light and visible light towards the light guide plate 151, and the light guide plate 151 conducts the invisible light and the visible light towards the light emitting surface of the liquid crystal display panel 10 to form emergent light and display backlight respectively.

Wherein, the side of the light guide plate 151 can be opened with a groove, and the light source plate F1 can be accommodated in the groove of the side of the light guide plate 151, thereby improving the light guide effect and the structural stability.

As shown in fig. 9, the backlight unit 15 further includes a reflective plate a1, the reflective plate a1 is disposed on a side of the light guide plate 151 facing away from the light exit surface of the lcd panel 10, and the reflective plate a1 is configured to reflect the invisible light and the visible light of the light guide plate 151 everywhere in the direction away from the light exit surface side of the lcd panel 10 back to the light guide plate 151, and further transmit the invisible light and the visible light to the side of the light exit surface of the lcd panel 10 through the light guide plate 151.

Since the light guide plate 151 inevitably guides light in other directions deviating from the light exit surface side of the liquid crystal display panel 10, the reflection plate a1 effectively prevents light loss, and ensures that both the invisible light and the visible light emitted from the invisible light lamps 152 and the dry visible light lamps 153 are transmitted to one side of the light exit surface of the liquid crystal display panel 10.

As shown in fig. 9, the backlight unit 15 further includes a diffuse reflection plate M1, and the diffuse reflection plate M1 is disposed on a side of the light guide plate 151 facing the light exit surface of the lcd panel 10, and is used for scattering the light transmitted by the light guide plate 151 and facing the light exit surface of the lcd panel 10, so that the light becomes uniform light. That is, the diffuse reflection plate M1 is for realizing the light emission uniformity of visible light and invisible light.

Therefore, the light emitted upwards by the light guide plate 151, that is, the light emitted toward one side of the light exit surface of the liquid crystal display screen 10, is scattered by the diffuse reflection plate M1, so that the light distribution emitted by the light guide plate 151 is more uniform, the uniformity of the display brightness is improved, the uniformity of the reflected light is also more favorably improved, and the accuracy of fingerprint identification is improved.

Fig. 9 shows a light path diagram of the invisible light and the visible light transmitted to the light emitting surface side of the liquid crystal display panel 10 through the light guide plate 151, the reflection plate a1 and the diffuse reflection plate M1, and as can be seen from fig. 9, the invisible light and the visible light emitted by the invisible light lamp 152 and the dry visible light lamp 153 are both transmitted to one side of the light emitting surface of the liquid crystal display panel 10 through the cooperation of the light guide plate 151, the reflection plate a1 and the diffuse reflection plate M1, and the light transmitted by the light guide plate 151 is converted into uniform parallel light vertically facing the light emitting surface of the liquid crystal display panel 10 through the diffuse reflection plate M1.

Referring back to fig. 2, the liquid crystal display panel 10 further includes an upper polarizer 18, and the upper polarizer 18 is disposed on a side of the filter layer 11 facing the light emitting surface of the liquid crystal display panel 10. As shown in fig. 9, the backlight unit 15 further includes a lower polarizing plate Z1.

The upper polarizing plate 18, the lower polarizing plate Z1, and the liquid crystal layer 12 together realize the display function of each sub-pixel on the liquid crystal display panel 10, that is, the normal image display function of the liquid crystal display panel 10.

Fig. 10 is a schematic plan view of a backlight unit 15 in another embodiment. As shown in fig. 10, in another embodiment, the plurality of non-visible light lamps 152 are disposed at the first side end D1 and the second side end D2 of the light guide plate 151, the plurality of visible light lamps 153 are disposed at the third side end D3 of the light guide plate 151, and the third side end D3 is connected between the first side end D1 and the second side end D2.

That is, in another embodiment, the non-visible light lamps 152 and the visible light lamps 153 are separately disposed at different lateral ends of the light guide plate 151, and the non-visible light lamps 152 are disposed at two opposite lateral ends of the light guide plate 151.

As shown in fig. 10, the backlight unit 15 further includes two invisible light source panels F2 and a visible light source panel F3, wherein some of the invisible light lamps 152 are disposed on one of the invisible light source panels F2 and then disposed at the first side end D1 by being spaced apart from the invisible light source panel F2, and other some of the invisible light lamps 152 are disposed at another one of the invisible light source panels F2 by being spaced apart from the invisible light source panel F2 and then disposed at the second side end D2 by being spaced apart from the invisible light source panel F2. The plurality of visible light lamps 153 are arranged on the visible light source board F3 at intervals, and then are arranged at the third side end D3 through the visible light source board F3.

Referring to fig. 11 and 12 together, fig. 11 is a schematic diagram of a backlight unit 15 taken along a section line II-II in fig. 10, and fig. 12 is a schematic diagram of a backlight unit 15 taken along a section line III-III in fig. 10. As shown in fig. 11, the invisible light lamps 152 are disposed on the side surfaces S2 of the first side end D1 and the second side end D2 of the light guide plate 151, which are opposite to each other, at the first side end D1 and the second side end D2 of the light guide plate 151. As shown in fig. 12, the visible light lamps 153 are disposed at the third side end D3 of the light guide plate 151 and are also disposed on the side surface S3 of the third side end D3 of the light guide plate 151.

As shown in fig. 11 and 12, the light guide plate 151 includes an upper surface 1511 and a lower surface 1512 parallel to the light emitting surface of the liquid crystal display panel 10, and the two side surfaces S2 and the side surface S3 are both peripheral side walls connected to the upper surface 1511 and the lower surface 1512.

Further, the invisible light lamps 152 and the visible light lamps 153 are respectively disposed on the invisible light source plate F2 and the visible light source plate F3, then two invisible light source plates F2 of the invisible light lamps 152 are respectively disposed on the side surface S1 of the first side end D1 and the side surface S2 of the second side end D2 of the light guide plate 151, and the visible light source plate F3 of the visible light lamps 153 is disposed on the side surface S3 of the third side end D3 of the light guide plate 151. The invisible light lamps 152 and the visible light lamps 153 respectively emit invisible light and visible light towards the light guide plate 151, and the light guide plate 151 conducts the invisible light and the visible light towards the light emitting surface of the liquid crystal display panel 10 to form emergent light and display backlight respectively.

The side surface S1 of the first side end D1, the side surface S2 of the second side end D2, and the side surface S3 of the third side end D3 of the light guide plate 151 may be respectively provided with a groove, and the two light source boards F2 and F3 may be respectively accommodated in the corresponding grooves, so as to improve the light guide effect and improve the structural stability.

As shown in fig. 10, the invisible light lamps 152 disposed at the first side end D1 and the second side end D2 of the light guide plate 151 are asymmetrically disposed at the two opposite side ends. Obviously, in other embodiments, the invisible light lamps 152 disposed at the first side end D1 and the second side end D2 of the light guide plate 151 are disposed at the two opposite side ends in a symmetrical manner.

As shown in fig. 11 and 12, the backlight unit 15 also includes a reflective plate a1, the reflective plate a1 is disposed on a side of the light guide plate 151 facing away from the light exit surface of the lcd panel 10, and the reflective plate a1 is used for reflecting the invisible light and the visible light from the light guide plate 151 to the light guide plate 151 everywhere in the direction away from the light exit surface side of the lcd panel 10, and further transmitting the invisible light and the visible light to the side of the light exit surface of the lcd panel 10 through the light guide plate 151.

The backlight unit 15 further includes a diffuse reflection plate M1, and the diffuse reflection plate M1 is disposed on a side of the light guide plate 151 facing the light exit surface of the liquid crystal display panel 10, and is configured to scatter the light transmitted by the light guide plate 151 and facing the light exit surface of the liquid crystal display panel 10, so that the light becomes uniform light.

Also, the backlight unit 15 further includes a lower polarizing plate Z1.

Therefore, the visible light lamps 153 and the invisible light lamps 152 are respectively arranged at different side ends of the light guide plate 151, the number of the visible light lamps 153 and the number of the invisible light lamps 152 can be effectively increased, the number of the original visible light lamps 153 cannot be reduced due to the increase of the invisible light lamps 152, and the influence on the brightness of the display backlight is avoided. And, further, all set up invisible light lamp 152 through two relative side at light guide plate 151, can promote the intensity and the degree of consistency that are used for fingerprint identification's invisible outgoing light, improve fingerprint identification's precision and sensitivity.

Fig. 13 is another schematic diagram of the backlight unit 15 taken along the section line II-II in fig. 10. As shown in fig. 13, in other embodiments, the light guide plate 151 also includes an upper surface 1511 and a lower surface 1512 parallel to the light emitting surface of the liquid crystal display panel 10. The upper surface 1511 is a surface facing the light emitting surface of the liquid crystal display screen, and the lower surface 1512 is a surface facing away from the light emitting surface of the liquid crystal display screen. In other embodiments, as shown in fig. 13, the invisible light lamps 152 are disposed at the opposite first side end D1 and the second side end D2 of the light guide plate 151 near the lower surface 1512 of the light guide plate 151 at the opposite first side end D1 and the second side end D2.

That is, in other embodiments, the invisible light lamps 152 are disposed on the lower surface 1512 near/at the opposite first side end D1 and second side end D2 of the light guide plate 151, and are arranged at intervals along the long sides of the first side end D1 and the second side end D2.

As shown in fig. 13, the backlight unit 15 includes, in addition to the reflection plate a1, two sidewall reflection plates a2 respectively disposed at sides of the first side end D1 and the second side end D2, and the two sidewall reflection plates a2 continue to extend a preset distance while passing through the lower surface in a direction from the upper surface to the lower surface. Two opposite ends of the reflection plate a1 and the first and second side ends D1 and D2 have a spacing region, and the invisible light lamps 152 are disposed on the spacing region of the lower surface 1512 of the light guide plate.

Specifically, the plurality of invisible light lamps 152 are disposed on two invisible light source plates F2, each invisible light source plate F2 is provided with a plurality of invisible light lamps 152 arranged at intervals, light exit surfaces (i.e., surfaces from which the invisible light lamps 152 emit light rays) of the two invisible light source plates F2 are both inclined with respect to the lower surface 1512 of the light guide plate 151, and the light exit surfaces of the two invisible light source plates F2 face the corresponding side wall reflection plates a2 at a certain angle.

The invisible light emitted by the invisible light lamps 152 on the two invisible light source plates F2 is firstly emitted to the corresponding side wall reflection plate a2, then reflected into the light guide plate 151 by the side wall reflection plate a2, and then transmitted by the light guide plate 151 in the direction of the light exit surface side of the liquid crystal display panel 10 to form the emergent light respectively.

The visible light lamp 153 may be disposed on the side surface S3 of the third side end D3 of the light guide plate 151 as shown in fig. 11 and 12.

Here, as shown in fig. 13, the backlight unit 15 also includes a diffusive reflective plate M1 and a lower polarizer Z1.

Fig. 14 is a schematic diagram of an optical path for performing fingerprint image imaging by touching or pressing the liquid crystal display 10 with a finger in an embodiment.

As shown in fig. 2 and 14, the liquid crystal display panel 10 further includes a glass cover 19, and the glass cover 19 is disposed at an outermost side of the light emitting surface side of the liquid crystal display panel 10 and is used for protecting the liquid crystal display panel 10.

As in the above embodiment, when fingerprint recognition is required, the backlight unit 15 may emit invisible outgoing light toward the light exit surface side of the liquid crystal display panel 10, i.e., upward, and the invisible outgoing light passes through the TFT driving layer 14 and the image sensor layer 16 and the pixel electrode layer 13 to reach the liquid crystal layer 12. When the liquid crystal display panel 10 performs fingerprint recognition, the liquid crystal cell 121 on the liquid crystal layer 12 is in an on state, and invisible emergent light emitted from the backlight unit 15 passes through the liquid crystal cell 121 on the liquid crystal layer 12, passes through the upper optical sheet 111, the upper polarizing sheet 18 and the glass cover plate 19, and is reflected at the interface between the finger T1 and the glass cover plate 19. Because the refractive indexes of the fingerprint ridges of the fingers and the glass cover plate are similar, most of invisible light of the fingerprint ridges can penetrate through the fingerprint ridges, and the small part of invisible light is reflected at the interface of the fingerprint glass; at the fingerprint valley, most of invisible light is reflected at the interface between the fingerprint and the glass, and only a small part of invisible light penetrates through the glass at the fingerprint valley to the outside because the refractive index of air is much smaller than that of glass.

The invisible light reflected by the interface between the glass cover plate 19 and the finger T1 passes through the upper polarizer 18 and the filter 111 and reaches the liquid crystal layer 12, and the liquid crystal cell 121 corresponding to the liquid crystal layer 12 is still in an on state, so that the reflected invisible light passes through the liquid crystal layer 12 and reaches the image sensor layer 16, and the invisible light is received by the invisible light sensor 162 on the image sensor layer to form an image of the fingerprint image.

The signal quantities generated by the invisible light sensors 162 of the three adjacent light sensing units can be added to obtain a photoelectric signal finally used for corresponding to one pixel point in the imaging fingerprint image, so that the signal-to-noise ratio of the pixel can be improved, and the finally obtained image quality can be improved.

Referring to fig. 15 and 16 together, fig. 15 is a schematic plan view of an image sensor layer 16 in another embodiment, and fig. 16 is a schematic laminated structure of the liquid crystal display panel 10 in another embodiment. The emergent light includes visible emergent light, the image sensor layer 16 includes a plurality of visible light sensors 163 arranged in an array, and the plurality of visible light sensors 163 are configured to receive visible reflected light of the visible emergent light reflected by a barrier including a finger on the light-emitting surface side of the liquid crystal display, and convert the visible reflected light into an electro-optical signal for generating an image including a fingerprint image.

As shown in fig. 16, the backlight unit 15 is used for emitting visible emergent light, and the visible emergent light can be used as display backlight, and can be reflected by a barrier of a finger for performing optical fingerprint imaging under the screen, so that the structure of the backlight unit 15 of the existing liquid crystal display screen 10 does not need to be changed, and the cost is reduced.

As shown in fig. 15, the number of the visible light sensors 163 is equal to the number of all the sub-pixels of the lcd panel 10, wherein the size of the visible light sensors 163 is smaller than the size of the area of the sub-pixels, and each visible light sensor 163 is disposed in the area of a corresponding sub-pixel.

In the present embodiment, each of the red, green and blue sub-pixels has a corresponding visible light sensor 163, and the adjacent three visible light sensors 163 corresponding to the red, green and blue sub-pixels respectively form a minimum imaging unit C1. The imaging unit C1 can be used as a unit corresponding to a pixel of a fingerprint image to generate an optoelectronic signal for forming a pixel value of the pixel, and the like.

As shown in fig. 16, during fingerprint identification, the backlight unit 15 emits visible light, and the visible light passes through the image sensor layer 16, passes through the liquid crystal cell 121 in the liquid crystal layer 12 in an on state, and then passes through the optical filter 111 to obtain monochromatic light including red, green, and blue. The red, green and blue monochromatic lights are transmitted upwards, and are reflected at the interface of the finger T1 and the glass cover plate 19 after passing through the upper polarizer 18 and the glass cover plate 19. Similarly, the refractive index difference between the air and the glass is larger, and the refractive index difference between the finger and the glass is smaller, so that the monochromatic light (red, green and blue) is reflected more at the fingerprint valley and less at the fingerprint ridge, and the reflected light intensity difference of the fingerprint valley ridge can be used for identifying the ridge line of the fingerprint to be detected. After the visible emergent light is reflected by a barrier including a finger on the light-emitting surface side of the liquid crystal display panel to form visible reflected light, the visible reflected light passes through the red filter R1, the green filter G1 and the blue filter B1 to form red reflected light, green reflected light and blue reflected light respectively, and the red reflected light, the green reflected light and the blue reflected light are received by the three visible light sensors 163 in the imaging unit C1, which correspond to the red sub-pixel, the green sub-pixel and the blue sub-pixel respectively, so as to generate a photoelectric signal with gamma value information.

Fig. 17 is a schematic diagram illustrating the generation of photoelectric signals by three photo sensors 163. As shown in fig. 16, the three visible light sensors 163 respectively corresponding to the red, green and blue sub-pixels simultaneously sense the collected signals, and then the sum of the photoelectric signals generated by the three visible light sensors 163 is outputted as the photoelectric signal of one minimum imaging unit C1 for generating the fingerprint image.

Therefore, in the mode of implementing the off-screen optical fingerprint by using visible light, since the visible light forms light with a corresponding color after passing through the optical filter 111, the photoelectric signal generated by the visible light sensor 163 carries information such as a gamma value, and a fingerprint image generated based on the photoelectric signal with the gamma value information has the information of the gamma value, which can further improve the security of fingerprint identification.

The number of the visible light sensors 163 may also be less than the number of all the sub-pixels of the lcd panel 10. For example, the visible light sensor 163 may be disposed only in a partial pixel unit P1 in which a visible light sensor 163 corresponds to a corresponding region of the red sub-pixel, the green sub-pixel, and the blue sub-pixel of each pixel unit P1, and the adjacent three visible light sensors 163 corresponding to the red sub-pixel, the green sub-pixel, and the blue sub-pixel respectively constitute a minimum imaging unit C1.

For the way of realizing the fingerprint under the screen by the visible light, every three visible light sensors 163 respectively corresponding to the red sub-pixel, the green sub-pixel and the blue sub-pixel can be further designed to be respectively sensitive to only the red monochromatic light, the green monochromatic light and the blue monochromatic light, that is, respectively only to receive the red monochromatic light, the green monochromatic light and the blue monochromatic light. Specifically, only monochromatic light of the corresponding color can be received by changing the depth of the light sensing layer of the visible light sensor 163.

Referring back to fig. 17, specifically, for one imaging unit C1, the visible light sensor 163 corresponding to the red sub-pixel outputs an electrical signal VR after receiving the red visible light (R), the visible light sensor 163 corresponding to the green sub-pixel outputs an electrical signal VG after receiving the green visible light (G), and the visible light sensor 163 corresponding to the blue sub-pixel outputs an electrical signal VB. after receiving the blue visible light (B), the electrical signals VB, VG, VR are amplified by α, β, and γ times, respectively, and then added together, so as to obtain the minimum imaging unit electrical signal Vo., where specific values of the amplification coefficients α, β, and γ depend on the light transmittance of the liquid crystal layer 12, the filter 111, the upper polarizer 18, and the glass cover plate 19 in practical applications, and the actual photoelectric conversion efficiency of the visible light sensors 163 corresponding to the red sub-pixel, the green sub-pixel, and the blue sub-pixel needs to be adjusted and determined according to the parameters of the actual process.

Wherein the image sensor layer 16 may further include a signal amplifier to amplify the photoelectric signal output from the visible light sensor 163.

In some embodiments, the TFT driving layer 14 is configured to apply a driving voltage to the corresponding pixel electrode 131 under a predetermined condition to drive the liquid crystal cell 121 to be in the on state, where the predetermined condition includes a condition that a finger of a user is detected to approach or press the liquid crystal display 10 and a condition that the liquid crystal display 10 performs content display.

As shown in fig. 5, the TFT driving layer 14 includes an electrode TFT driving array 141, the electrode TFT driving array 141 is configured to be connected to each pixel electrode 131, and is configured to apply a driving voltage to at least a portion of the pixel electrodes 131, wherein the electrode TFT driving array 141 applies the driving voltage to the pixel electrodes 131 located in a target area of the liquid crystal display panel 10 in response to an operation of a finger of a user approaching or pressing the target area, so that the liquid crystal cells 121 in the target area are in an on state, and thus the emergent light can be emitted to the light emitting side of the liquid crystal display panel 10, and the reflected light can be incident on the image sensor layer 16 of the liquid crystal display panel 10 and received by the corresponding photo sensors 161.

The liquid crystal display screen 10 is further provided with a proximity sensor or a pressure sensor for detecting whether a finger is approaching or pressing the liquid crystal display screen 10, and generating a sensing signal when detecting that the finger is approaching or pressing the liquid crystal display screen 10. Wherein, the proximity sensor can be a brightness sensor, an infrared sensor and the like, and the pressure sensor can be a piezoresistor and the like. The proximity sensors or the pressure sensors may be arranged in the liquid crystal display 10 in an array manner, wherein the number of the proximity sensors or the pressure sensors may be much less than the number of the pixels, so that the approximate position of the finger touching or pressing may be determined, and the proximity sensors or the pressure sensors and the coordinates on the liquid crystal display 10 form a one-to-one correspondence relationship in advance.

As shown in fig. 1, the electronic device 100 further includes a processor 20, and the processor 20 is configured to determine a coordinate position range touched or pressed by a finger according to a corresponding relationship between the proximity sensor or the pressure sensor and a coordinate on the liquid crystal display 10 when receiving a sensing signal generated by the proximity sensor or the pressure sensor, and determine an area of the liquid crystal unit 121 corresponding to the coordinate position range as the target area.

As shown in fig. 1 and fig. 5, the electronic device 100 further includes a display driving circuit 30, the electrode TFT driving array 141 includes a plurality of driving units 1411 arranged in an array, and each driving unit 1411 is electrically connected to a corresponding pixel electrode 131.

In fig. 5, the pixel electrode 131 is laminated and displayed above the driving unit 1411 of the TFT driving layer 14 for convenience of illustration. In practice, the projection of the pixel electrode 131 onto the TFT driving layer 14 and the driving unit 1411 may not overlap.

As shown in fig. 5, the display driving circuit 30 is electrically connected to the row driving units 1411 through the scan lines Gate1, and is configured to provide a scan voltage to each row driving unit 1411 in turn, so as to control the corresponding row driving unit 1411 to be turned on.

The display driving circuit 30 is electrically connected to the column driving units 1411 through Data lines 1, and is configured to provide driving voltages for the driving units 1411 in the corresponding column. When the driving unit 1411 in a certain row is turned on, the driving voltage provided by the display driving circuit 30 to the driving unit 1411 in a certain column can be applied to the corresponding pixel electrode 131 by turning on the driving unit 1411 in the row and the column, so that the TFT driving layer 14 applies the driving voltage to the corresponding pixel electrode 131.

When receiving a sensing signal generated by the proximity sensor or the pressure sensor, the processor 20 determines a coordinate position range touched or pressed by a finger according to a corresponding relationship between the proximity sensor or the pressure sensor and a coordinate on the liquid crystal display screen 10, determines an area corresponding to the coordinate position range as the target area, and then determines a plurality of target driving units 1411 located in the target area. The processor 20 controls the display driving circuit 30 to apply a scan voltage to the target driving units 1411 through the scan lines Gate1 connected to the target driving units 1411, thereby controlling the target driving units 1411 to be turned on, and controls the display driving circuit 30 to apply a driving voltage to the target driving units 1411 through the Data lines Data1 connected to the target driving units 1411, the driving voltage being applied to the corresponding pixel electrodes 131 through the turned-on target driving voltages, respectively. Accordingly, an electric field is formed in a target region of the liquid crystal display panel 10, and liquid crystal molecules of the liquid crystal cell 121 in the target region are driven to rotate and be in an on state.

Therefore, in some embodiments of the present application, whether the optical fingerprint is implemented by visible light or invisible light, the fingerprint identification can be implemented under a black screen. That is, without performing fingerprint recognition when the liquid crystal display 10 is lit, the liquid crystal cell 121 in the target area may be controlled to be in the on state according to the user touching or pressing the target area of the liquid crystal display 10 in the black state, and visible light or invisible light is allowed to enter or exit the liquid crystal display 10, so as to realize the optical fingerprint under the screen.

Obviously, when the liquid crystal display panel 10 is in the bright display state, since most of the liquid crystal cells 121 are necessarily already in the on state, the fingerprint recognition can be directly performed in the bright display state.

Fig. 18 is a specific circuit diagram of the driving unit 1411. Each of the driving units 1411 has the same structure, and as shown in fig. 18, only a specific structure of one driving unit 1411 is illustrated for description. Each driving unit 1411 may include a TFT (thin film transistor) Q1, a Gate G of the TFT Q1 is connected to a corresponding scan line Gate1 and is electrically connected to the scan interface of the display driving circuit 30 through the corresponding scan line Gate1, a drain D of the TFT Q1 is connected to a corresponding data line Date1 and is connected to the data interface of the display driving circuit 30 through a corresponding data line D1, and a source S of the TFT Q1 is connected to the pixel electrode 131.

Accordingly, when the display driving circuit 30 supplies a scan voltage to the driving unit 1411, the gate of the TFT Q1 is turned on by receiving the scan voltage, so that, when the display driving circuit 30 outputs a driving voltage to the driving unit 1411 through the data line Date1, the driving voltage can be applied to the pixel electrode 131 correspondingly connected through the turned-on TFT Q1.

The scan voltage may be a high level voltage, and the TFT Q1 may be a high level conducting transistor, such as an NMOSFET. Obviously, in other embodiments, the scan voltage may also be a low level voltage, and the TFT Q1 may be a low level conducting transistor, such as a PMOSFET.

Fig. 19 is a schematic view of a partial structure of the TFT driving layer 14 in another embodiment. In another embodiment, the TFT drive layer 14 further includes a photo TFT drive array 142. That is, the TFT driving layer 14 includes a light sensing TFT driving array 142 in addition to the electrode TFT driving array 141.

The photo TFT driving array 142 is connected to each photo sensor 161, and is configured to apply an enabling voltage to the photo sensor 161 located in a target area of the liquid crystal display panel 10 in response to an operation of a finger of a user approaching or pressing the target area, so that the photo sensor 161 in the target area is in an operating state, and can receive a reflected light reflected by a barrier including the finger on a light emitting surface side of the liquid crystal display panel 10 and convert the reflected light into a photoelectric signal.

That is, in some embodiments, the plurality of photo sensors 161 are normally in a standby or non-operating state, and only when a finger approaches or presses the liquid crystal display 10, the photo sensors 161 in the target area of the liquid crystal display 10 that are approached or pressed by the finger of the user are enabled to be in an operating state, that is, in a normal operating state that can receive the reflected light reflected by the barrier including the finger on the light emitting surface side of the liquid crystal display 10 and convert the reflected light into an electro-optical signal. Therefore, energy consumption can be effectively reduced.

As shown in fig. 1 and fig. 19, the electronic device 100 further includes a light sensing driving circuit 40, the light sensing TFT driving array 142 includes a plurality of enabling units 1421 arranged in an array, and each enabling unit 1421 is electrically connected to a corresponding light sensor 161.

The light sensor driving circuit 40 is electrically connected to each enabling unit 1421 through a plurality of enabling lines E1, and is configured to provide an enabling signal to the corresponding enabling unit 1421, so that the enabling unit 1421 triggers the corresponding light sensor 161 to be in a working state after receiving the enabling signal.

Further, when receiving the sensing signal generated by the proximity sensor or the pressure sensor, the processor 20 determines a coordinate position range touched or pressed by the finger according to the corresponding relationship between the proximity sensor or the pressure sensor and the coordinates on the liquid crystal display 10, and determines an area corresponding to the coordinate position range as the target area, and then determines the plurality of light sensors 161 located in the target area and the target enabling unit 1421 connected thereto. The processor 20 controls the light sense driving circuit 40 to apply an enable signal to the plurality of target enable units 1421 through a plurality of enable signals E1 connected to the plurality of target enable units 1421, so as to trigger the corresponding light sensors 161 to be in an operating state.

In fig. 19, for convenience of illustration, the photo sensor 161 is stacked on the enable unit 1421 of the TFT driving layer 14. In practical cases, the projection of the photo sensor 161 on the TFT driving layer 14 and the enabling unit 1421 may not overlap.

Fig. 20 is a specific circuit diagram illustrating the connection between the enabling unit 1421 and the photo sensor 161 according to an embodiment. Each enable unit 1421 has the same structure, and as shown in fig. 20, only one specific structure of the enable unit 1421 is illustrated for description. Each enabling unit 1421 may include a TFT (thin film transistor) Q2, and the photo sensor 161 may be a photo diode D0.

The gate G of the TFT Q2 is connected to the corresponding enable line E1, the drain of the TFT Q2 is connected to the cathode of the photodiode D0, and the source of the TFT Q2 is connected to a signal output line X1.

As shown in fig. 20, the enabling unit 1421 further includes a voltage terminal Vbias, and a storage capacitor C2 connected between the voltage terminal Vbias and the drain of the TFT Q2, and the anode of the photodiode D0 is connected to a voltage terminal Vbias.

When the gate G of the TFT Q2 receives an enable signal from an enable line E1, the TFT Q2 is turned on, so that the cathode of the photodiode D0 is electrically connected to a signal output line X1, when a reflected light is transmitted to the photodiode D0, the resistance of the photodiode D0 changes, and a current flows through the photodiode D0 to generate a corresponding photoelectric signal because the TFT Q2 is in a conducting state.

Each signal output line X1 is connected to the processor 20, and the processor 20 receives all the photoelectric signals output by the photo sensors 161 and forms a fingerprint image through an imaging process.

The enable signal may be a high-level signal, and the TFT Q2 may be a high-level conducting transistor, such as an NMOSFET. Obviously, in other embodiments, the enable signal may also be a low-level voltage, and the TFT Q2 may be a low-level conducting transistor, such as a PMOSFET.

The photodiode D0 is a photodiode sensitive to invisible light when the photosensor 161 is the invisible photosensor 162, and the photodiode D0 is a photodiode sensitive to visible light when the photosensor 161 is the visible photosensor 163.

As shown in fig. 1, the electronic device 100 further includes a memory 50, and the memory 50 stores a fingerprint image template. The processor 20 is further configured to compare and match the generated fingerprint image with the fingerprint image template in the memory after generating the fingerprint image, and confirm that the fingerprint identification authentication is successful when the matching is passed.

In some embodiments, for the way in which the optical fingerprint is implemented by invisible light, the invisible light lamps 152 may default to an off state and only turn on when a user's finger is near or presses a target area of the liquid crystal display.

Specifically, the electronic device 100 may further include a power supply unit (not shown) configured to at least respectively supply power to the invisible light lamp 152 and the visible light lamp 153, and in a normal state, the power supply unit does not supply power to the invisible light lamp 152, and the processor 20 controls the power supply unit to supply power to the invisible light lamp 152 to generate invisible light when receiving the sensing signal generated by the proximity sensor or the pressure sensor. Therefore, the invisible light lamp 152 is turned on when needed, and energy consumption can be effectively reduced.

The power supply unit may also be used to supply power to other components of the electronic device 100, such as the processor 20, the display driving circuit 30, the light sensing driving circuit 40, the memory 50, and the like.

Fig. 21 is a schematic view of an electronic device 100 according to the present application. As shown in fig. 20, the electronic device 100 includes a liquid crystal display 10, the image sensor layer 16 is integrated in the liquid crystal display 10, and as mentioned above, the image sensor layer 16 includes a plurality of photo sensors 161 arranged in an array, so as to realize full-screen optical fingerprint recognition.

The memory 50 may include a high speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), a plurality of magnetic disk storage devices, a Flash memory device, or other volatile solid state storage devices.

The Processor 20 may be a Processor integrated with an image Processor, and may specifically be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, a discrete Gate or transistor logic device, a discrete hardware component, and the like. The general purpose processor may be a microprocessor or the processor may be any conventional processor or the like

The electronic device according to the embodiment of the present invention may include various handheld devices such as a Mobile phone with a liquid crystal display, a tablet computer, a digital camera, etc., a vehicle-mounted device, a wearable device, a computing device, or other processing devices connected to a wireless modem, and various forms of User Equipment (UE), a Mobile Station (MS), etc. For convenience of description, the above-mentioned apparatuses are collectively referred to as electronic devices.

It should be noted that, for simplicity of description, the above-mentioned method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above embodiments of the present invention are described in detail, and the principle and the implementation of the present invention are explained by applying specific embodiments, and the above description of the embodiments is only used to help understanding the method of the present invention and the core idea thereof; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. The utility model provides a liquid crystal display of integrated fingerprint identification function which characterized in that, liquid crystal display includes:

the filter layer comprises filters arranged in an array;

the liquid crystal layer comprises a plurality of liquid crystal units which are arranged in an array;

the pixel electrode layer comprises a plurality of pixel electrodes which are arranged in an array manner, wherein the pixel electrodes correspond to the liquid crystal units and the optical filters one to one;

the TFT driving layer is used for applying a driving voltage to at least part of the pixel electrodes so as to drive at least part of the corresponding liquid crystal units to be in an opening state;

the backlight unit is used for emitting emergent light towards the light-emitting surface side of the liquid crystal display screen, and when the TFT driving layer applies driving voltage to at least part of the pixel electrodes to drive at least part of the liquid crystal units to be in an open state, the emergent light reaches the light-emitting surface side of the liquid crystal display screen after passing through at least part of the liquid crystal units in the open state and the corresponding optical filters;

the image sensor layer comprises a plurality of light sensors which are arranged in an array, the light sensors are used for receiving reflected light rays which are reflected by a blocking object of the emergent light rays, the blocking object is located on the light emergent surface side of the liquid crystal display screen and comprises a finger, and the light sensors convert the reflected light rays into photoelectric signals so as to be used for generating images including fingerprint images.

2. The liquid crystal display according to claim 1, wherein the liquid crystal layer is located between the filter layer and the pixel electrode layer, the TFT driving layer is located between the pixel electrode layer and the backlight unit, the image sensor layer is located between the pixel electrode layer and the TFT driving layer or between the liquid crystal layer and the pixel electrode layer, the filter layer is disposed near a light emitting surface side of the liquid crystal display, and the backlight unit is disposed far away from the light emitting surface side of the liquid crystal display.

3. The lcd panel of claim 2, wherein the plurality of filters arranged in an array comprises a plurality of filter sets, each filter set comprises a red filter, a green filter and a blue filter, the red filter, the green filter and the blue filter respectively correspond to a red sub-pixel, a green sub-pixel and a blue sub-pixel of the lcd panel, and each filter set corresponds to a pixel unit consisting of a red sub-pixel, a green sub-pixel and a blue sub-pixel.

4. The lcd panel of claim 3, wherein the outgoing light emitted from the backlight unit comprises invisible outgoing light, the image sensor layer comprises a plurality of invisible light sensors arranged in an array, and the invisible light sensors are configured to receive invisible reflected light reflected by the blocking object and convert the invisible reflected light into photoelectric signals for generating images including fingerprint images.

5. The LCD panel of claim 4, wherein the number of invisible light sensors is equal to or less than the number of all sub-pixels of the LCD panel, wherein the size of the invisible light sensors is smaller than the size of the area of the sub-pixels, and each invisible light sensor is disposed in the area of a corresponding sub-pixel.

6. The lcd panel of claim 4, wherein the backlight unit comprises a light guide plate and a plurality of invisible light lamps, the plurality of invisible light lamps are arranged at intervals at least one side end of the light guide plate, the plurality of invisible light lamps are used for emitting invisible light, and the light guide plate is used for guiding the invisible light towards the light emitting surface side of the lcd panel to form the invisible emergent light.

7. The lcd panel of claim 6, wherein the backlight unit further comprises a plurality of visible light lamps spaced apart from each other at least at one side of the light guide plate, the plurality of visible light lamps being configured to emit visible light, and the light guide plate being configured to transmit the visible light toward the light-emitting surface of the lcd panel to form a display backlight.

8. The LCD panel of claim 7, wherein the invisible light lamps and the visible light lamps are disposed at the same lateral end of the light guide plate, and the invisible light lamps and the visible light lamps are doped.

9. The lcd panel of claim 7, wherein the plurality of non-visible light lamps are disposed at opposite first and second lateral ends of the light guide plate, and the plurality of visible light lamps are disposed at a third lateral end of the light guide plate, the third lateral end being connected between the first and second lateral ends.

10. The lcd panel of claim 3, wherein the outgoing light comprises visible outgoing light, and the image sensor layer comprises a plurality of visible light sensors arranged in an array, the plurality of visible light sensors being configured to receive visible reflected light from the visible outgoing light reflected by the obstruction and convert the visible reflected light into an electro-optical signal for generating an image including a fingerprint image.

11. The lcd panel of claim 10, wherein the number of visible light sensors is equal to the number of all sub-pixels of the lcd panel, wherein the size of the visible light sensors is smaller than the size of the area of the sub-pixels, and each visible light sensor is disposed in the area of a corresponding sub-pixel.

12. The lcd panel of claim 11, wherein the backlight unit comprises a light guide plate and a plurality of visible light lamps spaced apart from each other at least at one side of the light guide plate, the plurality of visible light lamps are configured to emit visible light, and the light guide plate is configured to transmit the visible light toward the light-emitting surface of the lcd panel to form the visible emergent light.

13. The lcd panel of claim 11, wherein the exiting light is also used simultaneously for a display backlight of the lcd panel.

14. The lcd panel of any one of claims 1-13, wherein the TFT driving layer is configured to apply a driving voltage to the corresponding pixel electrode to drive the liquid crystal cell to be in the on state under a predetermined condition, and the predetermined condition includes a condition that a finger of a user is detected to approach or press the lcd panel and a condition that the lcd panel is in a content display state.

15. The lcd panel of claim 14, wherein the lcd panel is further provided with a proximity sensor or a pressure sensor for detecting whether a finger is approaching or pressing the lcd panel.

16. The lcd of claim 14, wherein the TFT driving layer comprises an electrode TFT driving array for connecting to each pixel electrode for applying a driving voltage to at least a portion of the pixel electrodes, wherein the electrode TFT driving array applies a driving voltage to the pixel electrodes located in a target area of the lcd in response to a finger of a user approaching or pressing the target area to turn on the liquid crystal cells in the target area, so that the emergent light can be emitted to the light-emitting side of the lcd and the reflected light can be incident on the image sensor layer of the lcd and received by the corresponding photo sensors.

17. The lcd of claim 16, wherein the TFT driving layer further comprises a photo TFT driving array, the photo TFT driving array is connected to each photo sensor, and configured to apply an enabling voltage to the photo sensor located in the target area in response to a finger of a user approaching or pressing the target area of the lcd, so that the photo sensor in the target area is in an active state, and receive a reflected light reflected by a barrier including the finger on the light emitting side of the lcd, and convert the reflected light into an electro-optical signal for generating an image including a fingerprint image.

18. The lcd panel of claim 6 or 12, wherein the backlight unit further comprises a diffuse reflection plate disposed on a side of the light guide plate facing the light exit surface of the lcd panel, for making the light guided by the light guide plate and facing the light exit surface of the lcd panel uniform.

19. The liquid crystal display panel of claim 2, further comprising a common electrode layer disposed between the filter layer and the liquid crystal molecule layer, wherein the common electrode layer is configured to provide a common zero potential, and when the TFT driving layer applies a driving voltage to at least a portion of the pixel electrodes, an electric field is formed between the at least a portion of the pixel electrodes and the common electrode layer to drive liquid crystal molecules in at least a portion of the corresponding liquid crystal cells to rotate to be in an on state.

20. An electronic device comprising the liquid crystal display panel according to any one of claims 1 to 19.