CN110160458B

CN110160458B - Light sensing film, display panel and detection method of bending state of display panel

Info

Publication number: CN110160458B
Application number: CN201910481298.5A
Authority: CN
Inventors: 郭远辉
Original assignee: BOE Technology Group Co Ltd; Wuhan BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Wuhan BOE Optoelectronics Technology Co Ltd
Priority date: 2019-06-04
Filing date: 2019-06-04
Publication date: 2021-11-05
Anticipated expiration: 2039-06-04
Also published as: CN110160458A

Abstract

The invention discloses a light sensing film, a display panel and a detection method of a bending state of the display panel. The optical sensing film comprises an optical sensing unit, a signal receiving unit electrically connected with one end of the optical sensing unit and a signal output unit electrically connected with the other end of the optical sensing unit, wherein the optical sensing unit is configured to be capable of generating a sensing state corresponding to the polarization state of light passing through the optical sensing unit, so that the signal output unit outputs an electric signal corresponding to the polarization state of the light. The display panel includes a display substrate and a photo-sensing film disposed on one side of the display substrate. The detection method realizes the detection of the bending state of the display panel, and the display panel can react according to the stress bending state of the display panel, so that the display mode of the display panel corresponds to the bending state, the display effect of the display panel is improved, and the application range and the field of the flexible display panel are widened.

Description

Light sensing film, display panel and detection method of bending state of display panel

Technical Field

The invention relates to the technical field of display, in particular to a light sensing film, a display panel and a detection method of a bending state of the light sensing film and the display panel.

Background

With the continuous development of display technology, the advent of flexible display devices has satisfied the demand of people for display devices that can be bent. Compared with the traditional rigid display device, the flexible display device has the advantages of lightness, thinness, flexibility, good mechanical property and the like. Successful mass production of the flexible display device is not only beneficial to manufacturing of a new generation of high-end smart phones, but also brings profound influence on application of wearable equipment due to the characteristics of low power consumption and flexibility, and the flexible display device is widely applied along with continuous penetration of personal intelligent terminals.

However, the flexible display device in the prior art cannot detect the bending state of the flexible display device, thereby limiting the application field of the flexible display device. For example, when the mobile phone is bent from a flat state to a wrist state, the display state of the wrist mobile phone still maintains the original flat display mode because the mobile phone cannot detect the bent state of the mobile phone, thereby affecting the use of the user.

Disclosure of Invention

An object of an embodiment of the present invention is to provide an optical sensing film, a display panel and a method for detecting a bending state of the display panel, so as to detect the bending state of a flexible display panel.

In order to solve the above technical problem, an embodiment of the present invention provides an optical sensing film, including an optical sensing unit, a signal receiving unit electrically connected to one end of the optical sensing unit, and a signal output unit electrically connected to the other end of the optical sensing unit, where the optical sensing unit is configured to be capable of generating a sensing state corresponding to a polarization state of light passing through the optical sensing unit, so that the signal output unit outputs an electrical signal corresponding to the polarization state of the light.

Optionally, the optical sensing unit includes a plurality of sensing subunits with a grating structure, the setting directions of different sensing subunits are different, the signal receiving unit is electrically connected with one end of each sensing subunit, and the signal output unit is electrically connected with the other end of each sensing subunit.

Optionally, the sensing subunits comprise a first sensing subunit and a second sensing subunit, the first sensing subunit is arranged along a first direction, and the arrangement direction of the second sensing subunit is perpendicular to the first direction.

Optionally, the sensing subunit further includes a third sensing subunit, and an angle between the arrangement direction of the third sensing subunit and the first direction is 45 °.

Optionally, the sensing subunit further comprises a fourth sensing subunit, and an angle between the arrangement direction of the fourth sensing subunit and the first direction is 135 °.

Optionally, the sensing subunit includes a plurality of sensor bars arranged in parallel at intervals, and a gap between two adjacent sensor bars is less than or equal to 100 nm.

Optionally, the material of the sensing subunit includes a photosensitive sensing material.

Optionally, the lateral dimension and the longitudinal dimension of the light sensing unit are both 0.6mm to 1.0 mm.

In order to solve the above technical problem, an embodiment of the present invention further provides a display panel, including a display substrate and the photo-sensing film as described above, where the photo-sensing film is disposed on one side of the display substrate.

Optionally, the number of the light sensing films is multiple, and the multiple light sensing films are arranged on the display substrate in an array manner.

Optionally, the display substrate is a liquid crystal display substrate, the display substrate includes an array substrate and a color film substrate which are oppositely disposed, and the light sensing film is disposed on a surface of one side of the array substrate facing the color film substrate. 12. The display panel of claim 9, wherein the display substrate comprises an OLED substrate and a polarizer disposed on a light exit side of the OLED substrate, and wherein the light sensing film is disposed on a side of the polarizer facing away from the OLED substrate.

In order to solve the above technical problem, an embodiment of the present invention further provides a method for detecting a bending state of a display panel, where the display panel is the display panel described above, and the method includes:

obtaining an electric signal output by the signal output unit after the display panel is stressed;

obtaining the current polarization state of the display panel after being stressed according to the electric signal;

and obtaining the stressed bending state of the display panel according to the current polarization state.

Optionally, the obtaining a stressed bending state of the display panel according to the current polarization state includes:

comparing the current polarization state with the initial polarization state of the display panel to obtain the polarization state change;

obtaining the stress bending state of the display panel according to the corresponding relation between the polarization state change and the stress bending state,

the initial polarization state is the polarization state of light rays passing through the display panel before the display panel is stressed.

According to the display panel provided by the embodiment of the invention, the optical sensing film is attached to one side surface of the display substrate, the polarization state change of light passing through the display panel after the display panel is bent can be known by detecting the electric signal output by the optical sensing film signal output unit, so that the polarization state change of the display panel is further obtained, and the stress bending state of the display panel can be obtained according to the corresponding relation between the polarization state change and the stress bending state. After the stress bending state of the display panel is known, the display panel can react according to the stress bending state of the display panel, so that the display mode of the display panel corresponds to the bending state of the display panel, the display effect of the display panel is improved, and the application range and the field of the flexible display panel are widened.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a schematic structural diagram of a light-sensing film;

FIG. 2 is a diagram illustrating the polarization direction of a first polarized light incident on a light sensor cell according to an embodiment;

FIG. 3 is a schematic diagram of a sensor subunit of FIG. 1;

FIG. 4 is a schematic structural diagram of a display panel according to a second embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of the display panel shown in FIG. 4;

FIG. 6 is a schematic view of a transmission axis of the polarizer of FIG. 5;

FIG. 7a is a diagram illustrating a stressed state of the display panel shown in FIG. 4;

FIG. 7b is a schematic diagram of circularly polarized light;

FIG. 8a is a schematic view of the display panel under a further increased force on the basis of FIG. 7 a;

FIG. 8b is a schematic diagram of the polarization state of the display panel under the stress condition shown in FIG. 8 a;

FIG. 9 is a schematic diagram of a display panel in one embodiment;

FIG. 10 is a diagram of a display panel according to another embodiment.

Description of reference numerals:

1-a signal receiving unit; 2-a light sensing unit; 21-a first sensing subunit;

22-a second sensing subunit; 23-a third sensing subunit; 24-a fourth sensing subunit;

4-a signal output unit; 51-a display substrate; 53-light sensing film;

52-a polarizer; 61-an array substrate; 62-color film substrate;

63-a liquid crystal layer; 64-a first polarizer; 65-backlight module;

66 — a second polarizer; 71-an OLED substrate; 72-an organic thin film layer;

73-a third polarizer; 74-cover plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The technical contents of the present invention will be described in detail by specific embodiments.

The first embodiment:

fig. 1 is a schematic structural view of a photo-sensing film. As shown in fig. 1, the photo-sensing film includes a signal receiving unit 1, a photo-sensing unit 2, and a signal output unit 4. The signal receiving unit 1 is electrically connected to one end of the light sensing unit 2, and the signal output unit 4 is electrically connected to the other end of the light sensing unit 2. The light sensing unit 2 is configured to be able to generate a sensing state corresponding to a polarization state of light passing through the light sensing unit 2, so that the signal output unit 4 outputs an electrical signal corresponding to the polarization state of light.

The signal receiving unit 1 is configured to receive an electrical signal input to the optical sensing film, and after the electrical signal received by the signal receiving unit 1 passes through the optical sensing unit 2, a corresponding electrical signal is output from the signal output unit 4.

In the light sensing film of the embodiment of the present invention, the light sensing unit 2 is configured to generate the sensing state corresponding to the polarization state of the light passing through the light sensing unit 2, so that when the sensing states of the light sensing unit 2 are different, correspondingly, the signal output unit 4 can output different electrical signals, that is, the signal output unit 4 outputs an electrical signal corresponding to the polarization state of the light, so that by analyzing the electrical signal output by the signal output unit 4, the polarization state of the light passing through the light sensing unit 2 can be obtained, and further the polarization direction and the state of the light passing through the light sensing unit 2 can be known.

When the display panel is not bent, the polarization state of light passing through the display panel is not changed. When the display panel atress is crooked, the refracting index of each direction of display panel is different, make the polarization state change of display panel rete, and then make the polarization state of the light through display panel change, and the change of polarization state is corresponding with the crooked state of display panel atress, that is to say, the polarization state change behind the light process display panel is corresponding with the crooked situation of display panel's atress, consequently, when setting up the light sensing film on the display panel surface, can learn the change of display panel polarization state after the atress is crooked in order to know the signal of telecommunication of signal output unit output through the light sensing film, and then learn the crooked state of display panel's atress. After the stress bending state of the display panel is known, the display panel can react according to the stress bending state of the display panel, so that the display mode of the display panel corresponds to the bending state of the display panel, the display effect of the display panel is improved, and the application range and the field of the flexible display panel are widened.

As shown in fig. 1, the light sensing unit 2 includes a plurality of sensing sub-units in a grating structure, that is, the sensing sub-units include a plurality of sensing bars 201 arranged in parallel at intervals. The arrangement directions of the different sensing subunits are different, namely the arrangement directions of the sensing bars in the different sensing subunits are different. The signal receiving unit 1 is electrically connected with the input end of each sensing subunit, and the signal output unit 4 is electrically connected with the output end of each sensing subunit. The detection state of each sensing subunit corresponds to a first angle, and the first angle is an included angle between the polarization direction of light passing through the sensing subunit and the arrangement direction of the sensing bars 201 in the sensing subunit. The material of the sensing sub-unit is photosensitive sensing material, and the material of the sensing sub-unit comprises at least one of amorphous silicon, polycrystalline silicon, microcrystalline silicon and metal oxide material. The metal Oxide material may be Indium Gallium Zinc Oxide (IGZO) or Indium Tin Zinc Oxide (ITZO). Therefore, when the sensor subunits absorb different amounts of light, their conduction ratios are different.

The detection principle of the sensing subunit is as follows:

the sensing subunit of the grating structure is equivalent to a polarizing plate, when the polarization direction of the light passing through the sensing subunit is parallel to the arrangement direction of the sensing strips (the first angle is 0), the light can pass through the sensing subunit without being absorbed by the sensing subunit, namely, the light flux passing through the sensing subunit is maximum, the light quantity absorbed by the sensing subunit is minimum, and the detection state of the sensing subunit, namely, the conductivity is minimum; with the increase of an included angle (namely a first angle) between the polarization direction of the light and the arrangement direction of the sensing strips, the light flux passing through the sensing subunit is gradually reduced, the light quantity absorbed by the sensing subunit is gradually increased, and the conduction rate of the sensing subunit is gradually increased; when the polarization direction of the light passing through the sensor subunit is perpendicular to the arrangement direction of the sensor strips (the first angle is 90 °), the light flux passing through the sensor subunit is 0, the amount of light absorbed by the sensor subunit is the largest, and the detection state of the sensor subunit, i.e. the conductivity, is the largest. Therefore, the signal output unit 4 can output an electric signal corresponding to the detection state of the sensing subunit, depending on the detection state of the sensing subunit.

When the polarized light passes through the light sensing unit 2, the sensing strips of different sensing subunits are arranged in different directions, so that the detection state of each sensing subunit is different. Here, assuming that the polarization direction of the first polarized light entering the light sensing unit 2 is a vertical direction, as shown in fig. 2, fig. 2 is a schematic diagram illustrating the polarization direction of the first polarized light entering the light sensing unit in one embodiment.

In this embodiment, as shown in fig. 1, the light sensing unit 2 may include a first sensing subunit 21, and the sensing bars of the first sensing subunit 21 are arranged along a first direction, which is a horizontal direction in this embodiment. Then, the arrangement direction of the sensor bars of the first sensor subunit 21 is perpendicular to the polarization direction of the first polarized light, so that the light flux passing through the first sensor subunit is almost 0, the amount of light absorbed by the first sensor subunit is the largest, and the conductivity of the first sensor subunit 21 is the largest, i.e. the conductive state of the first sensor subunit 21 is good.

The light sensing unit 2 may further include a second sensing subunit 22, and the sensing bars 201 of the second sensing subunit 22 are arranged along a vertical direction, i.e. the arrangement direction of the sensing bars 201 of the second sensing subunit 22 is perpendicular to the first direction. Then, the sensor bars 201 of the second sensor sub-unit 22 are arranged in a direction parallel to the polarization direction of the first polarized light, so that the light flux passing through the second sensor sub-unit is at most about 100%, the amount of light absorbed by the second sensor sub-unit is at least, the conductivity of the second sensor sub-unit 22 is at least almost 0, and the second sensor sub-unit 22 is non-conductive and close to an insulating state.

The light-sensing unit 2 may further comprise a third sensing subunit 23, the sensor bars of the third sensing subunit 23 being arranged in a direction at an angle of 45 ° to the horizontal. Then, the arrangement direction of the sensor strips of the third sensor subunit 23 is at an angle of 45 ° to the polarization direction of the first polarized light, so that the light flux detected by the third sensor subunit 23 is 65% to 75% of the light flux passing through the second sensor subunit, the amount of light absorbed by the third sensor subunit 23 is about 25% to 35% of the amount of light absorbed by the first sensor subunit, the conductivity of the third sensor subunit 23 is 25% to 35% of the conductivity of the first sensor subunit, and the conductivity of the third sensor subunit 23 is higher than the conductivity of the second sensor subunit 21 and lower than the conductivity of the first sensor subunit 22.

The light-sensing unit 2 may further comprise a fourth sensing subunit 24, the sensor bars of the fourth sensing subunit 24 being arranged in a direction at an angle of 135 ° to the horizontal. The sensor strips of the fourth sensor sub-unit 24 are then arranged at an angle of 45 deg. to the polarization direction of the first polarized light, so that the light flux through the fourth sensor sub-unit 24 is substantially equal to the light flux through the third sensor sub-unit 23, and the conductivity of the fourth sensor sub-unit 24 is the same as the conductivity of the third sensor sub-unit 23, being 25% to 35% of the conductivity of the first sensor sub-unit.

Therefore, the intensities of the light rays passing through the light sensing units in different directions are different, so that the luminous fluxes passing through the sensing subunits at different angles are different, the detection states of the sensing subunits at different angles are different, and correspondingly, the signals output by the sensing subunits at different angles are different. As can be seen from the above analysis, the conduction rate of the sensing subunit is directly proportional to the first angle (i.e. the included angle between the polarization direction of the passing light and the arrangement direction of the sensing strip), i.e. the larger the first angle is, the larger the conduction rate of the sensing subunit is, the larger the corresponding electrical signal output by the signal output unit 4 is.

In fig. 1, the optical sensing unit 2 includes four sensing subunits, the signal receiving unit 1 is electrically connected to input terminals of the four sensing subunits, and the signal output unit 4 is electrically connected to output terminals of the four sensing subunits. The detection states of the four sensing subunits are different, and thus, the signal output unit 4 can output an electrical signal corresponding to the conduction state of each sensing subunit.

In order to reflect the detection states of the four sensing subunits, respectively, the signal output unit 4 may output a set of electric signals composed of four data, which correspond to the four sensing subunits, respectively. By analyzing a group of electric signals output by the signal output unit 4, the conduction states of the four sensing subunits can be respectively obtained, and then the polarization state of light passing through the light sensing unit and the change of the polarization state of the light after passing through the light sensing unit are obtained. Of course, the signal output unit 4 may also output an electrical signal corresponding to the four data, and by analyzing the electrical signal, the conduction states of the four sensing subunits may also be obtained respectively, so as to obtain the polarization state of the light passing through the light sensing unit, and the change of the polarization state of the light after passing through the light sensing unit.

In other embodiments, the light-sensing unit may further include more sensing subunits, for example, the light-sensing unit may further include a fifth sensing subunit and a sixth sensing subunit, the sensor bars of the fifth sensing subunit being arranged in a direction forming an angle of 22.5 ° with the horizontal direction, and the sensor bars of the sixth sensing subunit being arranged in a direction forming an angle of 157.5 ° with the horizontal direction.

It is easy to understand that when the electrical signal output by the signal output unit is too small, the signal amplifying unit can be arranged to amplify the electrical signal output by the signal output unit, so as to improve the detection result.

Fig. 3 is a schematic structural diagram of one sensing subunit in fig. 1. As shown in fig. 3, the sensing subunit is in a grating structure, the sensing subunit includes a plurality of sensing bars 201 arranged in parallel at intervals, and a gap d1 between two adjacent sensing bars 201 is less than or equal to 100nm, so that the sensing subunit has better sensing performance on the polarization state.

Second embodiment:

based on the inventive concept of the above embodiments, a second embodiment of the present invention provides a display panel. Fig. 4 is a schematic structural diagram of a display panel according to a second embodiment of the invention. As shown in fig. 4, the display panel includes a display substrate 51 and the photo-sensing film 53 as described above. The photo-sensing film 53 is disposed on one side of the display substrate 5. In a specific implementation, the photo-sensing film 53 may be attached on one side of the display substrate.

Fig. 5 is a schematic cross-sectional structure diagram of the display panel shown in fig. 4. In order to obtain polarized light, the display panel further includes a polarizer 52 disposed on the light-incident side of the photo-sensing film 53. In fig. 5, a polarizer 52 is disposed on the light incident side of the display substrate 51, and a photo-sensing film 53 is disposed on the light exiting side of the display substrate 51. In other embodiments, the polarizer 52 may also be disposed between the display substrate 51 and the photo-sensing film 53. In fig. 5, natural light or light from a backlight source becomes first polarized light after passing through the polarizer 52. When the display panel is in an unbent state, the polarization state of the light passing through the display panel is not changed, and the light still is the first polarized light, and the first polarized light is linearly polarized light.

Fig. 6 is a schematic diagram of a transmission axis of the polarizer in fig. 5, in which natural light or light from a backlight source becomes first polarized light after passing through the polarizer 52. Since the transmission axis direction of the polarizer is vertical, the polarization direction of the first polarized light 61 is vertical, as shown in fig. 2. The light sensing film is attached on the surface of the light exit side of the display substrate 51.

When the display panel is not deformed, the polarization state of the light passing through the display panel is not changed, that is, the light passing through the display panel is still the first polarized light. When the display panel atress is crooked, each position atress direction of display panel is different, the atress size is different, can lead to the refracting index of each position of flexible display panel different for the polarization state of display panel rete changes, and then makes the polarization state of the light through display panel change, and the change of display panel polarization state is corresponding with the crooked state of display panel atress. It is easy to understand that the change of the polarization state of the light passing through the display panel reflects the change of the polarization state of the display panel, and therefore, by detecting the electrical signal output by the optical sensing thin film signal output unit, the change of the polarization state of the light passing through the display panel can be obtained, and further, the change of the polarization state of the display panel can be obtained.

Table 1 shows the corresponding relationship between the polarization state changes and the stress state of several kinds of panels

Table 1 shows the corresponding relationship between the polarization state changes and the stress state of the display panel according to the embodiment of the present invention, and table 1 only shows the corresponding relationship between the polarization state changes and the stress state of the display panel. After the polarization state change of the light passing through the display panel after the display panel is bent is known, the stress state of the display panel can be obtained according to the corresponding relation between the polarization state change and the stress state. For example, the polarization state of light passing through the display panel is the Case 3 state obtained by the photo-sensing film, and the force direction and magnitude of the display panel can be obtained from table 1, and thus the bending state of the display panel can be obtained.

In order to obtain the bending state of the display panel at each position after being stressed, as shown in fig. 4, the display panel includes a plurality of photo-sensing films 53, and the plurality of photo-sensing films 53 are arranged in an array on the display substrate 51. In order to ensure the detection accuracy, as shown in fig. 4, the sensing period w of the photo-sensing film is 0.6mm to 1.0mm, that is, the length and width of the photo-sensing film are both 0.6mm to 1.0mm, and the number of the photo-sensing films disposed on the surface of the display substrate 51 may be specifically determined according to the size of the flexible substrate.

Fig. 7a is a schematic view of a stressed state of the display panel shown in fig. 4. In fig. 7a, the panel is forced to bend, the dotted line in the figure is the direction of the bending line, and the panel force direction F1 is perpendicular to the direction of the bending line. In fig. 7a, the angle between the force direction and the horizontal direction is 45 °, and the force magnitude is F1.

In fig. 7a, the principle of the electrical signal output from the photo-sensing film located at the position corresponding to the force applied in fig. 7a is as follows:

the magnitude of the force F1 determines the magnitudes of F1x and F1 y. F1x is a component force of F1 in the same direction as F1, and F1y is a component force of F1 in the direction perpendicular to F1. The larger F1 is, the larger F1x-F1y is, i.e., the difference between F1x and F1y is. If (F1x-F1y) × d is λ/4 (d is the thickness of the display panel and λ is the wavelength of light passing through the display panel), then after the display panel is bent as shown in fig. 7a, the first polarized light passing through the display panel is changed from linearly polarized light to circularly polarized light, as shown in fig. 7b, and fig. 7b is a schematic diagram of circularly polarized light. The light fluxes passing through the first sensor subunit 21, the second sensor subunit 22, the third sensor subunit 23 and the fourth sensor subunit 24 in the light sensing film at the stressed position are the same, the detection states, i.e., the conduction rates, of the four sensor subunits are the same, and the signal output unit 4 outputs the electric signals corresponding to the sensor subunits.

When the signal output unit 4 outputs an electrical signal corresponding to the stress shown in fig. 7a, by analyzing the electrical signal output by the signal output unit 4, it is known that the light fluxes passing through the four sensor subunits of the optical sensing film are the same, and the polarization state change of the light passing through the optical sensing film before and after the display panel is bent under stress is known, and according to the corresponding relationship between the polarization state change and the stress bending state, the stress direction and the stress magnitude of the display panel at the position of the optical sensing film can be known, and finally the bending state of the display panel at the corresponding position of the optical sensing film is obtained. It is easily understood that the curved state includes a curved direction, a curved radius.

Fig. 8a is a schematic diagram of the display panel further increased in force on the basis of fig. 7 a. As shown in fig. 8a, when F1 continues to increase so that (F1x-F1y) × d is λ/2, then, after the display panel is bent as shown in fig. 7a, the polarized light passing through the display panel is changed from linearly polarized light to another linearly polarized light, and the polarization direction of the polarized light is changed from vertical to horizontal, as shown in fig. 8b, and fig. 8b is a schematic diagram of the polarization state of the display panel under the condition of the force applied as shown in fig. 8 a. In the optical sensing film at the stressed position, the first sensing subunit 21 is arranged along the horizontal direction, is parallel to the polarization direction shown in fig. 8b, and has the largest light flux passing through it and the conductivity of 0; the second sensing subunit 22 is arranged along the vertical direction, which is perpendicular to the polarization direction shown in fig. 8b, and the flux of light passing through is minimum, and the conduction state of the second sensing subunit is good; the third and fourth sensing sub-units are each at 45 ° to the polarization direction shown in fig. 8b, the light flux passing through the third and fourth sensing sub-units is about 71% of the light flux passing through the first sensing sub-unit, the amount of light absorbed by the third and fourth sensing sub-units is about 29% of the light flux passing through the second sensing sub-unit 22, and the conductivity of the third and fourth sensing sub-units is about 29% of the conductivity of the second sensing sub-unit. The signal output unit 4 outputs an electric signal corresponding to each sensing subunit. Similarly, when the signal output unit 4 outputs an electrical signal corresponding to the stress shown in fig. 8a, by analyzing the electrical signal output by the signal output unit 4, the bending state of the display panel at the corresponding position of the photo-sensing film can be finally obtained.

The display substrate 51 is provided with a plurality of light sensing films arranged in an array manner, and according to the electric signals of the signal output units of the light sensing films, the polarization state change of the flexible display panel at each position can be obtained, so that the stress position, the stress size and the stress direction of the flexible display panel are obtained, the bending state of the flexible display panel at the corresponding position of each light sensing film is further obtained, and the integral bending state of the flexible display panel is obtained. After the integral bending state of the display panel is known, the display panel can react according to the stress bending state of the display panel, so that the display mode of the display panel corresponds to the bending state of the display panel, the display effect of the display panel is improved, and the application range and the field of the flexible display panel are widened. For example, when the display panel detects that the self-completion state is a wrist, the display panel can convert the display mode into the wrist mode, and the display effect of the display panel is improved.

It is easy to understand that, in practical implementation, in order to improve the accuracy of the obtained magnitude of the applied force, the applied force of the display panel can be corrected through the position distribution of the photo-sensing film on the display panel and the young's modulus of the display panel, so as to improve the accuracy of the obtained magnitude of the applied force of the display panel, and the obtained bending state of the display panel is closer to the true bending state of the display panel.

According to the display panel provided by the embodiment of the invention, the optical sensing film is arranged on the display substrate, the bending state of the panel can be detected according to the electric signal output by the optical sensing film, and then the display panel can make a response according to the bending state of the display panel, so that the display mode of the display panel corresponds to the bending state of the display panel, the display effect of the display panel is improved, and the application range and the field of the flexible display panel are widened.

FIG. 9 is a diagram illustrating a display panel according to an embodiment. As shown in fig. 9, the display panel is a liquid crystal display panel, and the display panel includes an array substrate 61 and a color filter substrate 62 which are oppositely disposed, and a liquid crystal layer 63 sandwiched between the array substrate 61 and the color filter substrate 62. The display panel further includes a plurality of photo-sensing films 53 disposed on a side of the array substrate 61 facing the liquid crystal layer 63, the plurality of photo-sensing films 53 being arranged in an array on the side of the array substrate facing the liquid crystal layer 63. The display panel further includes a first polarizer 64 disposed on a side of the array substrate 61 facing away from the liquid crystal layer 63, and a backlight module 65 disposed on a side of the first polarizer 64 facing away from the array substrate 61. A second polarizer 66 is disposed on the upper side of the color filter substrate 62.

In fig. 9, when light generated from the backlight unit 65 passes through the first polarizer 64, the light becomes linearly polarized. When the display panel is not deformed, the polarization state of light passing through the display panel is not changed and is still linearly polarized. When the display panel is deformed, the polarization state of light passing through the display panel changes, for example, from linear polarization to circular polarization. The mechanism of the change of the polarization state of the light passing through the display panel is as follows: when the display panel deforms, the phase difference of the display panel changes, so that the polarization state of the film layer of the display panel changes, and further the polarization state of light passing through the display panel changes.

Since the phase difference change of the display panel is proportional to the stress of the display panel and the thickness of the display panel, when the display panel is stressed and deformed, the phase difference of the display panel is changed.

The deformation and the phase difference of the display panel have the following corresponding relations: r_glass∞σ*SOC*d

Wherein σ is the shear force applied to the display panel, SOC is the photoelasticity of the display panel, and d is the thickness of the display panel.

σ ∞ 1/(R × E) R is a bending radius of the deformation, the smaller R is, the larger stress is, the Young modulus of the display panel is, the larger E is, and the larger stress is under the same deformation.

FIG. 10 is a diagram of a display panel according to another embodiment. As shown in fig. 10, the display panel is an Organic Light Emitting Diode (OLED) display panel. The display panel comprises an OLED substrate 71, an organic thin film layer 72 arranged on the OLED substrate 71, a third polarizer 73 arranged on the organic thin film layer 72, a cover plate 74 arranged on the third polarizer 73, and a plurality of light sensing films 53 arranged on the cover plate 74, wherein the plurality of light sensing films are arranged on the cover plate 74 in an array manner. In the display panel, after the display panel is deformed by force, the phase difference of the cover plate 74 changes, so that the polarization state of light passing through the display panel changes, the polarization state change of the corresponding position of the light sensing film of the display panel can be obtained through the light sensing film 53, the force direction and the force magnitude of the display panel can be further known, and the force-bearing bending state of the display panel can be further obtained.

It is easy to understand that the display panel of the embodiment of the present invention may be any product or component having a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, and a navigator.

According to the characteristics of the display panel of the embodiment of the present invention, an embodiment of the present invention further provides a method for detecting a bending state of the display panel, where the method includes:

s1: obtaining an electric signal output by the signal output unit after the display panel is stressed;

s2: obtaining the current polarization state of the display panel after being stressed according to the electric signal;

s3: and obtaining the stressed bending state of the display panel according to the current polarization state.

In one embodiment, S3 may include:

It is easy to understand that the polarization state of the light passing through the display panel reflects the polarization state of the display panel, and when the display panel is not stressed, the polarization state of the light passing through the display panel does not change, and when the display panel is stressed and bent, the polarization state of the light passing through the display panel changes. Therefore, the polarization state of the display panel after the light passes through the bending can be obtained through the electric signal output by the signal output unit after the display panel is stressed, and the polarization state reflects the current polarization state of the display panel after the display panel is stressed, namely the current polarization state of the light. After comparing the current polarization state with the initial polarization state, the polarization state change can be obtained, and then the stress bending state of the display panel can be obtained according to the corresponding relation between the polarization state change and the stress bending state.

In the description of the embodiments of the present invention, it should be understood that the terms "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An optical sensing film is characterized by comprising an optical sensing unit, a signal receiving unit electrically connected with one end of the optical sensing unit and a signal output unit electrically connected with the other end of the optical sensing unit, wherein the optical sensing unit is configured to detect the conduction rate of polarized light input by the signal receiving unit passing through the optical sensing unit and determine the polarization state of light rays of the polarized light after passing through the optical sensing unit according to the conduction rate, so that the signal output unit outputs an electric signal corresponding to the polarization state of the light rays of the polarized light after passing through the optical sensing unit;

the optical sensing unit comprises a plurality of sensing subunits with grating structures, the setting directions of different sensing subunits are different, the signal receiving unit is electrically connected with one end of each sensing subunit, and the signal output unit is electrically connected with the other end of each sensing subunit.

2. The light-sensing film of claim 1, wherein the sensing subunits comprise a first sensing subunit and a second sensing subunit, the first sensing subunit is disposed along a first direction, and the second sensing subunit is disposed perpendicular to the first direction.

3. The light-sensing film of claim 2, wherein the sensing subunit further comprises a third sensing subunit, and an angle between the arrangement direction of the third sensing subunit and the first direction is 45 °.

4. The light-sensing film of claim 2, wherein the sensing subunit further comprises a fourth sensing subunit, and an angle between the arrangement direction of the fourth sensing subunit and the first direction is 135 °.

5. The light-sensing film according to claim 1, wherein the sensor subunit comprises a plurality of sensor bars arranged in parallel at intervals, and a gap between two adjacent sensor bars is less than or equal to 100 nm.

6. The light-sensing film of claim 1, wherein the material of the sensing subunit comprises a photosensitive sensing material.

7. The light-sensing film according to claim 1, wherein the light-sensing unit has a transverse dimension and a longitudinal dimension of 0.6mm to 1.0 mm.

8. A display panel comprising a display substrate and the photo-sensing film according to any one of claims 1 to 7, the photo-sensing film being provided on one side of the display substrate.

9. The display panel according to claim 8, wherein the number of the photo-sensing films is plural, and the plural photo-sensing films are arranged in an array on the display substrate.

10. The display panel according to claim 8, wherein the display substrate is a liquid crystal display substrate, the display substrate comprises an array substrate and a color filter substrate which are oppositely arranged, and the photo-sensing film is arranged on a surface of one side of the array substrate facing the color filter substrate.

11. The display panel of claim 8, wherein the display substrate comprises an OLED substrate and a polarizer disposed on a light exit side of the OLED substrate, and wherein the light sensing film is disposed on a side of the polarizer facing away from the OLED substrate.

12. A method for detecting a bending state of a display panel, wherein the display panel is the display panel according to any one of claims 8 to 11, the method comprising:

obtaining an electric signal output by the signal output unit after the display panel is stressed; the electric signal corresponds to the polarization state of the light ray after the polarized light input by the signal receiving unit passes through the optical sensing unit, the conduction rate of the polarized light input by the signal receiving unit passing through the optical sensing unit is detected by the optical sensing unit, and the polarization state of the light ray after the polarized light passes through the optical sensing unit is determined according to the conduction rate;

13. The method for detecting according to claim 12, wherein the obtaining a forced bending state of the display panel according to the current polarization state comprises: