CN210401945U - Optical film layer structure, backlight module, display device and electronic equipment - Google Patents

Abstract

The application provides an optical film layer structure for gathering backlight light and penetrating detection light, which comprises a first film layer unit and a second film layer unit. Each film layer unit comprises a substrate and a plurality of microstructures arranged on the substrate at intervals. The substrate comprises an upper surface and a lower surface which are opposite in parallel, and the microstructures are arranged on the upper surface. Each microstructure includes a top surface facing away from the substrate, the top surface being parallel to at least a portion of the lower surface of the substrate opposite thereto. The propagation direction of at least one part of light penetrating through the film layer unit through the top surface is unchanged. The application also provides an optical film layer structure, a backlight module, a display device and an electronic device comprising the optical film layer structure.

Description

Optical film layer structure, backlight module, display device and electronic equipment

Technical Field

The application belongs to the technical field of optics, especially relates to an optics rete structure, backlight unit, display device and electronic equipment.

Background

Generally, in order to increase the backlight brightness of the lcd panel, an optical film for gathering the backlight light is usually disposed, such as: brightness Enhancement Film (BEF), prism sheet, and the like. The optical film layer gathers the scattered backlight light to the emergent direction of the display light of the liquid crystal display panel by arranging the raised microstructures on the light-transmitting substrate. However, although the shape of the existing microstructure has a strong gathering effect on the backlight light, the detection light emitted by or reflected by an external object and having a direction substantially opposite to the emitting direction of the backlight light has an obvious diverging effect, which is not beneficial to detecting the detection light after passing through the optical film layer, and thus the light path requirements of various under-screen sensing functions by arranging a hidden sensing module below the liquid crystal display panel cannot be met.

SUMMERY OF THE UTILITY MODEL

The application provides an optical film layer, a backlight module, a display device and an electronic device to solve the technical problems.

The embodiment of the application provides an optical film layer structure for it is light and see through the detection light to converge in a poor light, its characterized in that: the film comprises a first film unit and a second film unit, wherein each film unit comprises a substrate and a plurality of microstructures arranged on the substrate at intervals, the substrate comprises an upper surface and a lower surface which are opposite in parallel, the microstructures are arranged on the upper surface, each microstructure comprises a top surface back to the substrate, the top surface is at least parallel to the lower surface part of the substrate opposite to the top surface, and the propagation direction of at least one part of light penetrating through the film unit through the top surface is unchanged.

In some embodiments, the surface of the film layer unit of the spacing portion between the microstructures is at least parallel to the opposite part of the lower surface of the substrate, the propagation direction of at least a part of light rays passing through the film layer unit via the surface of the film layer unit of the spacing portion between the microstructures is unchanged, and the area of the top surface is smaller than the area of the spacing portion between the microstructures and is greater than or equal to one fourth of the area of the spacing portion between the microstructures.

In some embodiments, the microstructure includes a side surface, the side surface is not parallel to the opposite lower surface portion of the substrate, the propagation direction of at least a portion of light transmitted through the film layer unit via the side surface is changed, and an angle between the side surface and the upper surface of the substrate is greater than or equal to 40 degrees and less than or equal to 90 degrees.

In some embodiments, the microstructures on the first film layer unit and the second film layer unit are elongated terraces or elongated cuboids extending along a specific direction, wherein the first film layer unit and the second film layer unit are sequentially arranged along the optical path, and the extending directions of the microstructures on the first film layer unit and the second film layer unit are perpendicular to each other.

In some embodiments, the microstructure is a double-layer step shape, and includes a first protrusion disposed on the substrate and a second protrusion formed on a top surface of the first protrusion, the first protrusion is an elongated terrace or an elongated cuboid extending along a specific direction, the second protrusion is an upright elongated triangular prism formed on a top surface of the first protrusion, the elongated triangular prism extends along a direction same as that of the elongated terrace, and the propagation direction of at least a part of light rays of the film layer unit is unchanged through two unconnected planar regions respectively located on two opposite sides of the elongated triangular prism on the top surface.

In some embodiments, the sum of the areas of the top surfaces of the microstructures on the first film layer unit or the second film layer unit and the film layer unit surface of the spacing portion between the microstructures accounts for 63% or more of the area of the lower surface of the substrate, respectively, and the product of the two is 40% or more.

In some embodiments, the top surface of the microstructures, the bottom surface of the substrate, and the film layer unit surface of the spaces between the microstructures are all planar.

The present disclosure provides a backlight module for providing backlight light to a display panel and transmitting detection light emitted and/or reflected by an external object to a sensing module. The sensing module is used for executing corresponding sensing according to the detection light. The backlight module comprises the optical film layer structure according to the above embodiment, and the wavelength of the detection light is different from that of the backlight light.

In some embodiments, the optical film comprises a substrate and a rough glass-like microstructure formed on the substrate, and the diffusion effect of the diffusion sheet on the backlight light is greater than that of the detection light; or the diffusion sheet comprises a base material and diffusion particles doped on the base material, the diffusion particles are made of a material which can transmit infrared light or near infrared light and reflect visible light, and the average size of the diffusion particles is in the range of 380nm to 780 nm; or the diffusion sheet is a film layer with a nano porous structure, and a plurality of nano-scale pores are formed in the film layer; or the diffusion sheet is a quantum dot film layer arranged on the light-emitting surface of the light guide plate, the quantum dot film layer contains quantum dot materials, the quantum dot materials absorb blue backlight light and convert the blue backlight light into green backlight light and red backlight light respectively, the backlight module further comprises a backlight source used for providing backlight light, and the backlight source is a blue light-emitting source.

In certain embodiments, further comprising: the light guide plate comprises a light-emitting surface and a bottom surface opposite to the light-emitting surface; and the reflecting sheet is arranged on one side of the bottom surface and used for reflecting the backlight light transmitted out of the bottom surface of the light guide plate, wherein the reflecting sheet is made of a material which can transmit infrared light or near infrared light and reflect visible light.

The embodiment of the application provides a display device, which comprises a display panel and a backlight module. The display panel is used for displaying pictures, and the backlight module is used for providing backlight light to the display panel. The backlight module is the backlight module described in the above embodiment.

The embodiment of the present application provides an electronic device, which includes the display device of the above embodiment and a sensing module at least partially disposed under the display device, wherein the sensing module receives a detection light reflected or/and emitted from an external object through the display device to perform corresponding sensing.

In some embodiments, the sensing module includes a receiving unit disposed under the backlight module, and the receiving unit receives the detection light through the display panel and the backlight module to perform corresponding sensing.

In some embodiments, the sensing module further includes an emitting unit, the emitting unit is configured to emit the detection light to the external object, and the receiving unit is disposed below the backlight module or beside the display device and located in a non-display area.

In some embodiments, the sensing module is configured to perform one or more of fingerprint sensing, three-dimensional face sensing, and living body sensing.

The optical film layer structure, backlight module, display device and the electronic equipment that this application embodiment provided can not change the micro-structure shape of the detection light direction of propagation who sees through setting up on non-light tight basement, are convenient for carry out sensing under the screen to the detection light that sees through under the prerequisite that does not influence the display effect to can further improve electronic equipment's screen and account for than, promote electronic equipment's visual perception.

Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the present application.

Drawings

Fig. 1 is a schematic front view of an electronic device provided in a first embodiment of the present application.

Fig. 2 is a schematic structural diagram of the electronic device in fig. 1.

Fig. 3 is a schematic front view of an electronic device provided in a second embodiment of the present application.

Fig. 4 is a schematic structural diagram of the electronic device in fig. 3.

Fig. 5 is a schematic structural diagram of a display device according to a third embodiment of the present application.

Fig. 6 is a schematic structural diagram of a backlight module according to a fourth embodiment of the present disclosure.

Fig. 7 is a schematic structural diagram of a backlight module according to a fifth embodiment of the present application.

Fig. 8 is a schematic structural diagram of an optical film structure provided in a sixth embodiment of the present application.

Fig. 9 is an optical path diagram of the light in fig. 8 when the light passes through the first light transmission part and the second light transmission part.

Fig. 10 is a schematic structural diagram of an optical film structure provided in a seventh embodiment of the present application.

Fig. 11 is a schematic structural diagram of an optical film structure provided in an eighth embodiment of the present application.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application. In the description of the present application, it is to be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any order or number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; either mechanically or electrically or in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship or combination of two or more elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The following disclosure provides many different embodiments or examples for implementing different structures of the application. In order to simplify the disclosure of the present application, only the components and settings of a specific example are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repeat use is intended to provide a simplified and clear description of the present application and is not intended to suggest any particular relationship between the various embodiments and/or arrangements discussed.

Further, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the subject technology can be practiced without one or more of the specific details, or with other structures, components, and so forth. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of the application.

As shown in fig. 1 and fig. 2, a first embodiment of the present application provides an electronic device 1, such as a mobile phone, a notebook computer, a tablet computer, an electronic book, a personal digital assistant, a touch interactive terminal device, and the like. The electronic device 1 comprises a memory 12, a processor 14, a display device 3, and a sensing module 10 at least partially disposed on a back surface of the display device 3.

The display device 3 includes a display panel 30 and a backlight module 4 for providing backlight light to the display panel 30. The sensing module 10 is at least partially located below the backlight module 4 and directly faces the display area.

In the present embodiment, the display panel 30 is, for example, a liquid crystal display panel. However, the display panel 30 may alternatively be other suitable types of display panels, such as an electronic paper display panel. The sensing module 10 is used for implementing a corresponding under-screen sensing function through the display device 3. The sensing functions include, but are not limited to, two-dimensional and/or three-dimensional image sensing, three-dimensional stereo modeling, distance sensing, fingerprint recognition sensing, liveness sensing, and the like. The detection light needs to pass through each layer structure of the display device 3 to realize the interaction between the external object and the sensing module 10.

The memory 12 is used for storing data generated by the sensing module 10 during the sensing process, programs related to the sensing process, and data required for implementing the sensing-related functions, such as: and identity characteristic information of a legal user and the like required for identity recognition are carried out according to the sensed characteristic information of the external object. The processor 14 may be used to execute sensing related programs. The electronic device 1 can correspondingly execute related functions according to the sensing result of the sensing module 10, such as: the method comprises the following steps of screen extinguishing, screen locking unlocking, payment, account login, next-level menu entry, permission opening and the like.

In the present embodiment, the memory 12 and the processor 14 are components provided in the electronic device 1 independently of the sensor module 10. Alternatively, in some embodiments, the memory 12 or the processor 14 may also be an internal component of the sensor module 10.

In the present embodiment, the sensing module 10 includes a receiving unit 103. The receiving unit 103 is located below the backlight module 4. The detection light emitted or/and reflected by the external object is received by the receiving unit 103 after passing through the display panel 30 and the backlight module 4. The sensing module 10 implements corresponding sensing of the external object according to the received detection light. Such as, but not limited to, a user's finger, a user's face, or other suitable location, among others.

In particular, the receiving unit 103 comprises an optical modulator 104 and a sensor 106 located below the optical modulator 104. The light modulator 104 is configured to collect and normalize the detection light transmitted through the display device 3, so as to facilitate sensing of the detection light. The detection light is received by the sensor 106 after passing through the light modulator 104. The sensor 106 obtains the relevant information of the external object according to the detected light, for example, so as to realize corresponding sensing. The related information of the external object includes, but is not limited to, data such as an image, a position, and a biological feature of the external object. In the present embodiment, the light modulator 104 is a light beam collimating element such as a focus lens. The sensor 106 is an image sensor. However, in some embodiments, the optical modulator 104 may be omitted or replaced with other optical elements. The sensor 106 may also be other types of sensors.

In this embodiment, the sensing module 10 may further include a transmitting unit 102. The emitting unit 102 emits the detection light to the external object through the backlight module 4 and the display panel 30.

In particular, the emission unit 102 comprises a sensing light source. The detection light emitted by the sensing light source passes through the display device 3, is reflected by an external object and is turned back, passes through the display device 3 again, and is received by the receiving unit 103, so as to sense the relevant information of the external object, for example, sense the biological characteristic data of the external object for identification.

The detection light may have a specific wavelength according to sensing principles and application scenarios. In this embodiment, the detection light may be used for, but is not limited to, sensing a three-dimensional image of a fingerprint or a human face, and may be infrared or near-infrared light, and the wavelength range is 800nm to 1650 nm. Alternatively, in other embodiments, the detection light may be other suitable detection signals, such as ultraviolet light, ultrasonic waves, electromagnetic waves, and the like.

It is understood that, in other embodiments, the sensing module 10 may also integrate the corresponding memory 12 and the processor 14 to process the acquired sensing signal and output the sensing result to the electronic device 1 for direct utilization.

As shown in fig. 3 and 4, the second embodiment of the present application provides an electronic device 2, which is basically the same as the electronic device 1 provided in the first embodiment, and mainly differs therefrom in that: the emitting unit 202 of the sensing module 20 is not disposed on the back of the display device 3, but disposed outside the display area of the display device 3, such as but not limited to, on the side of the display panel 30, or on the side of the backlight module 4, or at another suitable position of the electronic device 1. The detection light emitted by the emitting unit 202 does not need to pass through the display device 3 to be projected on an external object, and is suitable for a scene with high emitting power of the emitting unit 202, such as: the transmitting unit 202 needs to project a light spot with a preset pattern to realize sensing of a three-dimensional surface on an external object. Other components of the sensing module 20, such as: the light modulator 204, the sensor 206, the memory 22, the processor 24, etc. may still be disposed on the back side of the display device 3 to reduce the occupation of the display area and improve the screen occupation ratio of the electronic apparatus 2.

It is understood that the light modulator 204 and the sensor 206 of the sensing module 20 may be disposed under any position in the display area of the display device 7, and the present application is not limited thereto.

As shown in fig. 5, the third embodiment of the present application provides a display device 3 that can be used in the electronic apparatus 1 described above. The display device 3 includes a display panel 30 and a backlight module 4. In the present application, the display panel 30 is described as an example of a liquid crystal display panel.

The display panel 30 includes, but is not limited to, a first substrate (not shown), a thin film transistor array circuit (not shown) disposed on the first substrate, a second substrate (not shown), a liquid crystal layer (not shown) disposed between the first substrate and the second substrate, an upper polarizer (not shown), a lower polarizer (not shown), a color filter (not shown), and a protective cover (not shown). The backlight module 4 provides a backlight beam for the display panel 30. The display panel 30 is disposed on the light-emitting side of the backlight module 4 to modulate the transmitted backlight according to the content to be displayed to realize display.

As shown in fig. 6, a backlight module 4 for use in the display device 3 is provided in the fourth embodiment of the present application. The backlight module 4 can be used to gather the backlight light emitted to the display panel 30 and the detection light reflected back by an external object or emitted by the external object itself so as to meet the requirements of providing the backlight for the display panel 30 and setting the sensing module 10 under the screen. The backlight module 4 includes a backlight source 40, a light guide plate 42, a reflective sheet 44, a diffusion sheet 46 and an optical film structure 5.

The light guide plate 42 includes a light emitting surface 420, a bottom surface 422 opposite to the light emitting surface 420, and a light incident surface 424 connected to the light emitting surface 420 and the bottom surface 422 and located on one side thereof. The backlight source 40 is disposed corresponding to the light incident surface 424, and is configured to emit backlight light into the light guide plate 42. The backlight light is mixed in the light guide plate 42 and then emitted from the light emitting surface 420. The reflective sheet 44 is disposed on the bottom surface 422 of the light guide plate 42, and is used for reflecting the backlight light back into the light guide plate 42 to improve the utilization rate of the backlight light. The reflective sheet 44 is made of a material that transmits infrared or near-infrared light and reflects visible light, so that backlight light in the visible wavelength range can be reflected back to the light guide plate 42 while infrared or near-infrared detection light can be transmitted.

The optical film structure 5 is disposed on one side of the light emitting surface 420 of the light guide plate 42, and is configured to gather the backlight light emitted from the light guide plate 42 to improve the backlight brightness provided by the backlight module 4. The optical film-layer structure 5 includes one or more film-layer units 50. In this embodiment, the optical film structure 5 includes two film units 50, namely a first film unit 501 and a second film unit 502. The first film-layer unit 501 and the second film-layer unit 502 are similar in structure. The first film layer unit 501 is described as an example.

The first film layer unit 501 includes a first optical surface 503 and a second optical surface 504 disposed oppositely. The first optical surface 503 and the second optical surface 504 are boundary surfaces when the backlight light and the detection light pass through the first film unit 501. That is, the backlight light and the detection light enter the first film layer unit 501 from one of the first optical surface 503 and the second optical surface 504, and the other one exits the first film layer unit 501. The first optical surface 503 is disposed near one side of the whole backlight module 4 for emitting backlight light. The second optical surface 504 is disposed near the light-emitting surface 420 side of the light guide plate 42. When the backlight light passes through the first film layer unit 501, the backlight light enters from the second optical surface 504 and then exits from the first optical surface 503. And the returned detection light is incident from the first optical surface 503 and then exits from the second optical surface 504 when passing through the first film layer unit 501. The distance between at least one portion of the first optical surface 503 and at least one portion of the second optical surface 504, through which the backlight light and the detection light pass through the same backlight light or detection light when passing through the first film layer unit 501, remains unchanged, i.e. they remain in a substantially parallel relationship with each other. The at least one portion of the first optical surface 503 is defined as a first light-transmitting portion 520, and the propagation direction of at least one portion of the detection light transmitted through the first film layer unit 501 via the first light-transmitting portion 520 is substantially unchanged, and the position of the light is shifted, so that the sensing module 10 (see fig. 2) disposed under the screen can sense the portion of the detection light.

The first optical surface 503 further includes a second light-transmitting portion 522 for converging light rays. The second light-transmitting portions 522 through which the same backlight light or detection light passes and the corresponding portions of the second optical surfaces 504 are not parallel, so that the propagation directions of the backlight light or detection light transmitted through the portions are obviously deflected, and the light can be gathered along a preset direction.

Optionally, the first film-layer unit 501 includes a substrate 500 and a microstructure 52 disposed on the substrate 500. The microstructures 52 are used to adjust the light path of the light. The substrate 500 and the microstructures 52 can be different or the same material. When the substrate 500 is made of the same material as the microstructure 52, the microstructure 52 may be directly formed on the substrate 500, or the substrate 500 may be coated with the same material as the substrate 500 and then formed into the microstructure 52. In this case, the detection light travels in a straight line passing between the substrate 500 and the microstructure 52. When the substrate 500 and the microstructures 52 are different materials, the materials of both are selected such that the refractive indices of the substrate 500 and the microstructures 52 are similar, for example: the difference in refractive index is less than or equal to 0.2. Therefore, the refraction of the detection light ray when passing through the interface between the substrate 500 and the microstructure 52 is small, and the influence of the refraction on the propagation direction of the light ray is negligible and is considered to be approximately straight-line propagation.

The upper and lower surfaces of the substrate 500 are planes parallel to each other. The microstructures 52 are formed on the upper surface of the substrate 500. The microstructures 52 are, for example, but not limited to, terraced structures. The terrace structure includes a top surface facing away from the upper surface of the substrate 500. The top surfaces of the terrace-like structures are parallel to the upper and lower surfaces of the substrate 500. The first light-transmitting portion 520 includes a top surface of the terrace-shaped microstructure 52. The position of the light is mainly translated when the light passes through the top surface of the microstructure 52 to the lower surface of the substrate 500, and the propagation direction of the light is basically unchanged. The side surfaces of the terrace-like microstructures 52 extend obliquely from the periphery of the top surface. Because the side surfaces of the step-shaped structures are not parallel to the upper and lower surfaces of the substrate 500, the propagation direction of the backlight light passing through the side surfaces can be obviously deflected, and the backlight light can be used as a second light-transmitting portion 522 for gathering the backlight light along a specific direction. The microstructures 52 on the substrate 500 are elongated protrusions extending in the same direction and parallel to each other.

In this embodiment, the other surface of each microstructure 52 except the bottom surface in contact with the substrate 500 can transmit light, and thus is used as the first optical surface 503 of the first film layer unit 501. The lower surface of the substrate 500 is the second optical surface 504 of the first film-layer unit 501.

The microstructures 52 are arranged at intervals. Accordingly, the first optical surface 503 further includes a film layer surface located in the spaced-apart region of the microstructure 52, where the film layer surface may be the upper surface of the substrate 500 exposed by the material of the microstructure 52 or the outer surface of the material layer of the microstructure 52 covered in the spaced-apart region of the substrate 500. The surface of the film layer in the spaced area is a plane parallel to the second optical surface 504, and can be used as the first light-transmitting portion 520 of the first optical surface 503, where the first light-transmitting portion 520 and the first light-transmitting portion 520 at the top surface of the microstructure 52 have different vertical distances from the lower surface of the substrate 500.

The extending direction of the microstructures 52 on the second film layer unit 502 is perpendicular to the extending direction of the microstructures 52 of the first film layer unit 501. The first film layer unit 501 and the second film layer unit 502 which are arranged up and down in this way enable a part of detection light to mainly generate translation of light positions when passing through the first film layer unit 501 and the second film layer unit 502, and the propagation direction is basically unchanged, so that the sensing module 10 arranged under the screen can obtain more accurate sensing information. Taking imaging as an example, the sensing module 10 can obtain an accurate image of the external object according to the detected light.

It can be understood that, since the first light-transmitting portion 520 can be used for sensing through the detection light and cannot converge the backlight light, and the second light-transmitting portion 522 can be used for converging the backlight light but can also change the direction of the passing detection light to be unfavorable for sensing, in order to better consider both functions of converging the backlight brightness and passing the detection light, the area ratio of the first light-transmitting portion 520 and the second light-transmitting portion 522 on the first optical surface 503 can be adjusted according to specific situations, but all adjustments made according to the technical idea of the present application should be covered in the protection scope of the present application.

Alternatively, in some embodiments, the microstructures 52 may be closely arranged without any space between them.

Alternatively, in some embodiments, the optical film layer structure 5 may be a single-layer film structure including only the monolithic film layer unit 50.

The optical film structure 5 will be described in detail in the following embodiments.

The diffusion sheet 46 is disposed at one side of the light emitting surface 420 of the light guide plate 42, and is used for diffusing the backlight light to achieve an atomization effect.

The diffusion sheet 46 diffuses backlight light in the visible wavelength range to transmit infrared or near-infrared detection light. For example: the wavelength range of the backlight light is 380nm to 760 nm. The wavelength range of the detection light is 800nm to 1650 nm. The diffusion of light by the diffuser 46 can be measured by haze. The haze is a percentage of the light intensity of the transmitted light, which is deviated from the incident direction by more than 2.5 degrees after passing through the diffusion sheet 46, to the light intensity of the original total incident light. The higher the haze of the light transmitted through the diffuser 46, the stronger the diffusion effect of the diffuser 46 on the light, and the diffuser 46 is considered to have the diffusion effect on the light when the haze exceeds 30%. Therefore, in the present embodiment, the diffusion sheet 46 has a haze of less than 30% with respect to the passing detection light.

The diffuser 46 may provide light diffusion by forming light diffusing structures on the substrate. In the present embodiment, the light diffusing structure may be a rough glass-like microstructure. The base material is a light-transmitting material, and can be selected from one or more of Polycarbonate (PC), polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET), or other materials meeting the light-transmitting requirement. The average size of the ground glass-like rough microstructure is within the visible light wavelength range of 380nm (Nanometer, nm) to 760nm, so that the ground glass-like rough microstructure has a relatively obvious diffusion effect on backlight light belonging to visible light and has relatively strong penetrability on infrared or near-infrared detection light with longer wavelength.

Alternatively, in other embodiments, the diffuser 46 may be made by incorporating diffusing particles on a substrate. When the backlight light passes through the diffusion sheet 46, the backlight light continuously passes through between the diffusion particles with different refractive indexes and the transparent base material, and multiple refraction, reflection and scattering phenomena occur, so that the optical diffusion effect is achieved. The diffusion particles may be made of a material that transmits infrared or near-infrared light and reflects visible light. The average size of the diffusion particles is within a visible light wavelength range of 380nm to 760nm, so that the diffusion particles can have a relatively significant diffusion effect on backlight light belonging to visible light and have relatively strong permeability to infrared or near-infrared detection light having a longer wavelength.

Alternatively, in other embodiments, the diffuser 46 is a film layer having a nanoporous structure. The material of the Nanoporous membrane layer may be, but is not limited to, a polyethylene fabric (nanopoorous polythylene textile). The polyethylene fabric material is formed with a plurality of small holes with nanometer-scale sizes, and the size range of the small holes is 100nm to 1000nm, so that the polyethylene fabric material has the characteristic of transmitting infrared or near infrared rays and scattering visible light.

The diffuser 46 may include an upper diffuser 461 and a lower diffuser 462. The upper diffusion sheet 461 and the lower diffusion sheet 462 have similar structures, and both can be used to diffuse backlight light and transmit detection light reflected by an external object. The upper diffuser 461 and the lower diffuser 462 may have respective functional biases such as: the upper diffusion sheet 461 emphasizes the fogging effect of the backlight light, and the lower diffusion sheet 462 has a relatively high transmittance of the backlight light. The arrangement sequence among the upper diffusion sheet 461, the lower diffusion sheet 462, the first film layer unit 501 and the second film layer unit 502, and among the upper diffusion sheet 461, the lower diffusion sheet 462 and the single film layer unit 50 is not particularly limited. For example, in the present embodiment, the first film layer unit 501 and the second film layer unit 502 are disposed between the upper diffusion sheet 461 and the lower diffusion sheet 462.

Alternatively, in other embodiments, the upper diffusion sheet 461 may be disposed between the first film layer unit 501 and the second film layer unit 502. The lower diffusion sheet 462 is disposed between the second film-layer unit 502 and the light guide plate 42.

Alternatively, as shown in fig. 7, a fifth embodiment of the present application provides a backlight module 4 that can be used in the display device 3, which is substantially the same as the backlight module 4 provided in the fourth embodiment, and the main differences are: the lower diffusion 462 sheet may be replaced with a quantum dot film layer. The quantum dot film layer 462 has a greater diffusion effect on backlight light than on infrared light or near-infrared light. The quantum dot film layer 462 contains a quantum dot material 463. The quantum dot material 463 may absorb blue backlight light and convert it into green backlight light and red backlight light, respectively. Therefore, the backlight source 40 only needs to be a blue light emitting source, and a part of the emitted blue backlight light is absorbed by the quantum dot material 463 in the quantum dot film layer 462 and then converted into green backlight light and red backlight light, and then mixed with the unabsorbed part of the blue backlight light to form white backlight light to be emitted. Since the quantum dot material 463 emits the converted light outward around itself during the conversion luminescence and has a scattering effect, the white backlight light converted by the quantum dot film layer 462 has better diffusivity. The quantum dot material does not absorb light in the infrared or near-infrared wavelength range, and thus can transmit the detection light.

As shown in fig. 8, a sixth embodiment of the present application provides an optical film structure 5 that can be used in the backlight module 4. The optical film layer structure 5 is used for gathering backlight light and enabling the propagation direction of at least part of the detection light to be basically unchanged and the position of the detection light to translate when the detection light penetrates through the optical film layer structure, so that the requirements of increasing display brightness and sensing by arranging a sensing module 10 (see fig. 2) below a screen are met.

The optical film structure 5 includes a first film unit 501 and a second film unit 502. The first film layer unit 501 and the second film layer unit 502 have similar structures, and the first film layer unit 501 is taken as an example for description.

The first film layer unit 501 includes a first optical surface 503 and a second optical surface 504 disposed oppositely. The first optical surface 503 and the second optical surface 504 are boundary surfaces when the backlight light and the detection light pass through the first film unit 501. That is, the backlight light and the detection light enter the first film layer unit 501 from one of the first optical surface 503 and the second optical surface 504, and the other one exits the first film layer unit 501. The first optical surface 503 is disposed near a side of the entire backlight module 4 (see fig. 6) that emits backlight light. The second optical surface 504 is disposed near a light emitting surface 420 (see fig. 6) of the light guide plate 42. When the backlight light passes through the first film layer unit 501, the backlight light enters from the second optical surface 504 and then exits from the first optical surface 503. And the returned detection light is incident from the first optical surface 503 and then exits from the second optical surface 504 when passing through the first film layer unit 501.

The distance between at least one portion of the first optical surface 503 and at least one portion of the second optical surface 504, through which the backlight light and the detection light pass through the same backlight light or detection light when passing through the first film layer unit 501, remains unchanged, i.e. they remain in a substantially parallel relationship with each other. The at least a portion of the first optical surface 503 is defined as a first light-transmitting portion 520.

The first optical surface 503 further includes a second light-transmitting portion 522 for converging light rays. The second light-transmitting portions 522 through which the same backlight light or detection light passes and the corresponding portions of the second optical surfaces 504 are not parallel, so that the propagation directions of the backlight light or detection light transmitted through the portions are obviously deflected, and the light can be gathered along a preset direction.

As shown in fig. 9, since the first light-transmitting portion 520 of the first optical surface and the corresponding portion of the second optical surface 504 through which the same light passes maintain a substantially parallel relationship, the propagation direction of the light transmitted through at least a portion of the first film layer unit 501 via the first light-transmitting portion 520 is substantially unchanged and the position is shifted by D according to the law of refraction of light. The portion of the detection light before entering from the first light-transmitting portion 520 is O1, and the portion of the same detection light after exiting from the corresponding second optical surface 504 is O2. It can be seen that the O2 portion after the detection light exits is mainly subjected to position shift D compared with the O1 portion before the detection light enters, and the transmission direction is unchanged.

It is understood that there may be a reasonable range of deviation in the parallel relationship between the first light-transmitting portion 520 and the corresponding portion of the second optical surface 504 due to manufacturing tolerance or machining precision.

According to the light refraction law, because the second light-transmitting portion 522 of the first optical surface 503 and the corresponding portion of the second optical surface 504 are not parallel to each other, the backlight light transmitted through the optical film structure 5 via the second light-transmitting portion 522 is deflected in a relatively obvious direction, and thus the backlight light can be gathered along a preset direction to improve the backlight brightness.

Specifically, the first film unit 501 includes a substrate 500 and a plurality of microstructures 52 formed on the substrate 500 for adjusting light. The substrate 500 includes an upper surface 508 and a lower surface 509 disposed parallel to the upper surface 508. The plurality of microstructures 52 are formed on the upper surface 508 of the substrate 500. The second optical surface 504 is a lower surface 509 of the substrate 500. The first optical surface 503 includes a portion of the outer surface of the microstructures 52 that is not in contact with the upper surface 508 of the substrate 500. If there are spaces between the microstructures 52, the first optical surface 503 may further include a portion of the upper surface 508 of the substrate 500 where the microstructures 52 are not formed. It will be understood that if the microstructures 52 are formed by coating a material on a substrate and then using a molding process, in the case where the material of the microstructures 52 is not completely removed in the spaced-apart regions between the microstructures 52, where the upper surface 508 of the substrate 500 is not exposed, the first optical surface 503 should strictly include the outer surface of the layer of microstructure material covering the spaced-apart regions, rather than the portions of the upper surface 508 of the substrate 500 that are located in the spaced-apart regions.

In this embodiment, the microstructure 52 is a rectangular parallelepiped structure, and includes a top surface 521 and a side surface 523 extending from a peripheral edge of the top surface 521, where the side surface 523 is perpendicular to the top surface 521. The top surface 521 of the microstructure 52 is the surface facing away from the substrate 500. The top surface 521 of the microstructure 52 is parallel to the lower surface 508 of the substrate 500. Correspondingly, the side 523 of the microstructure 52 is perpendicular to the lower surface 508 of the substrate 500. The top surface 521 is rectangular and is a continuously extending planar area. The microstructures 52 are spaced apart from each other. Because the top surface 521 of the microstructure 52 is parallel to the lower surface 509 of the substrate 500 as the second optical surface 504, the first light-transmitting portion 520 includes the top surface 521 of the microstructure 52 and a portion of the first optical surface 503 located in the spaced-apart region between adjacent microstructures 52. In addition, the side surface 523 of the microstructure 52 is not parallel to the lower surface 509 of the substrate 500 as the second optical surface 504, and thus the second light-transmitting portion includes the side surface 523 of the microstructure 52. After at least part of the detection light passes through the first film layer unit 501 via the first light transmission part 520, the propagation direction of the detection light is basically unchanged, and the position of the light is shifted, so that the transmitted detection light can be sensed easily and accurately. The propagation direction of the backlight light transmitted through the second light transmission portion 522 is deflected so that the light can be condensed in a specific direction.

In addition, due to the spaced arrangement among the plurality of microstructures 52, a portion of the first optical surface 503 located in the spaced area may also serve as the first light-transmitting portion 520, for example: the portions of the substrate 500 not covered by the microstructures 52 or the outer surface of the layer of microstructure 52 material covering the spaced areas. Therefore, the area of the first light-transmitting portion 520 is increased, so that the transmission direction of more detection light is not changed after the detection light passes through the first film unit 501, and thus the light flux of the detection light which can be better sensed can be increased, which is beneficial to improving the accuracy of the obtained sensing data.

The plurality of rectangular parallelepiped microstructures 52 on the first film layer unit 501 extend on the upper surface 508 of the substrate 500 along a predetermined direction to form a plurality of mutually parallel elongated cuboids. Similarly, the shape of the microstructure 52 on the second film-layer unit 502 is the same as the shape of the microstructure 52 on the first film-layer unit 501, but the extending direction of the rectangular-parallelepiped microstructure 52 on the second film-layer unit 502 is perpendicular to the extending direction of the rectangular-parallelepiped microstructure 52 on the first film-layer unit 501.

However, alternatively, the microstructures 52 may be other suitable protruding structures besides the rectangular parallelepiped structure, as long as the top surfaces of the protruding structures include surface portions that are substantially parallel to the lower surface of the substrate.

Further, the inventor has found through a large number of experiments and analysis verification that the percentage of the total area of the first light-transmitting portion 520 on the first film unit 501 or the second film unit 502 to the lower surface area of the substrate is respectively greater than or equal to 63%, and when the product of the two is greater than or equal to 40% and less than or equal to 100%, the amount of the detection light emitted from the optical film structure 5 with unchanged propagation direction is more appropriate, so that the sensing information obtained by the sensing module 10 according to the received detection light is more accurate. In addition, the converging effect of the optical film layer structure 5 on the incident backlight light is relatively suitable.

Preferably, the product of the two is greater than or equal to 50% and less than or equal to 100%.

The substrate 500 is made of a light-transmitting material, and transmits backlight light in a visible wavelength range and detection light in an infrared or near-infrared wavelength range. The material of the substrate 500 may be selected from any one or a combination of Polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or other materials that meet the above-mentioned light transmission requirements.

The microstructures 52 may be integrated with the substrate 500 and formed directly on the substrate 500 by a molding process. Alternatively, the microstructures 52 can also be separate portions that are distinct from the substrate 500. For example: firstly, a curable material is coated on the substrate 500, the curable material is made into a specific shape of the microstructure 52 by a molding process, and finally, the microstructure 52 is cured. It will be appreciated that the microstructures 52 are formed from a curable material having a refractive index substantially the same as the refractive index of the substrate 500, such that light rays undergo less refraction when passing through the interface between the microstructures 52 and the substrate 500, and the effect on the direction of propagation of the light rays is negligible and considered to travel approximately straight. In the present embodiment, the refractive index of the microstructure 52 is different from the refractive index of the substrate 500 by 0.2 or less.

As shown in fig. 10, a seventh embodiment of the present application provides an optical film structure 6 that can be used in the backlight module 4, and is substantially the same as the optical film structure 5 provided in the sixth embodiment, with the main differences: the microstructures 62 on the first film-layer unit 601 and the second film-layer unit 602 are in a long strip-shaped step-shaped structure.

Specifically, the elongated terrace-shaped microstructure 62 includes a top surface 621 and a side surface 623. The top surface 621 faces away from the substrate 600 and is parallel to the lower surface 609 of the substrate 600. The side surfaces 623 extend from the periphery of the top surface 621, and at least include a pair of side surfaces 623 extending from the top surface 621 along the long side of the elongated landing extension direction. The side 623 is inclined to the lower surface 609 of the substrate 600. The included angle between the side surface 623 and the top surface 621 is an obtuse angle.

The elongated step-shaped microstructures 62 on the same film unit 601 or 602 are also spaced apart from each other by a predetermined distance. The portion of first optical surface 603 that is within the spaced area remains substantially parallel to the lower surface 609 of substrate 600 that is second optical surface 604. The second optical surface 604 comprises a lower surface 609 of the substrate 600. The first light transmission portion 620 includes a top surface 621 of an elongated terrace and a portion of the first optical surface 603 located in a spacing area between adjacent microstructures 62, and the portion of the first optical surface 603 may be a portion of the substrate 600 not covered by the microstructures 62 or an outer surface of the microstructure 62 material layer covered in the spacing area. The second transparent portion 622 comprises a side 623 of the elongated terrace. In this embodiment, the elongated terrace has a single-layer elongated protrusion structure, and the top surface 621 of the elongated terrace, which is the first light-transmitting portion 620, is a continuously extended plane.

The first light transmission portions 620 parallel to the lower surface 609 of the substrate 600 are arranged in the spacing regions between the adjacent microstructures 62, so that a portion of the detection light which can pass through the first film unit 601 and the second film unit 602 without changing the propagation direction can be distributed more uniformly through the first light transmission portions 620, but if the area of the spacing regions is too large, the distribution density of the microstructures 62 is reduced, and the converging and brightening effect on the backlight light is affected. Therefore, the ratio of the spacing region to the microstructure 62 on the substrate 600 needs to be balanced. The inventors have demonstrated through a great deal of experiments and analyses that when the ratio of the area of the portion of the first optical surface 603 in the spaced area between the adjacent microstructures 62 to the area of the top surface 621 is greater than or equal to one fourth and less than one, the requirements of backlight brightness and uniformity of transmitted detection light can be well balanced. In the present embodiment, the adjacent microstructures 62 are uniformly distributed with the same interval therebetween.

As shown in fig. 11, an eighth embodiment of the present application provides an optical film structure 7 that can be used in the backlight module 4, and is substantially the same as the optical film structure 6 provided in the seventh embodiment, with the main differences: the first light-transmitting portion 720 of each microstructure 72 includes a plurality of planar regions that are not connected to each other, and the planar regions are connected to each other by the second light-transmitting portion 722. For example: in the present embodiment, the microstructure 72 has a two-step shape, and includes a first protrusion 723 provided on the substrate 700 and a second protrusion 724 formed on a top surface of the first protrusion 723. The first protrusion 723 is an elongated terrace extending in a specific direction. The second protrusion 724 is an upright elongated prism formed on the top surface of the first protrusion 723. The second protrusion 724 extends in the same direction as the first protrusion 723. The top surface of the elongated terraces remains parallel to the lower surface 709 of the base 700. The side surfaces of the elongated prism and the side surfaces of the elongated terrace are inclined to the lower surface 709 of the substrate 700. In this embodiment, the first light-transmitting portion 720 includes partial regions on the top surface of the elongated terrace, which are located on two opposite sides of the prism, and the partial regions are separated by the prism and are not connected to each other. The second light-transmitting portion 722 includes a side surface of the elongated prism and a side surface of the elongated terrace. The side surfaces of the strip-shaped prisms and the side surfaces of the strip-shaped prismatic tables form obtuse angles with the top surfaces of the strip-shaped terraces. The second light transmission portions 722 respectively connect a plurality of connected planar regions where the first light transmission portions 720 are located.

It is understood that the second protrusion 724 may be replaced by a groove structure formed on the top surface of the first protrusion 723 and having the same shape as the second protrusion 724. For example, the groove structure is an elongated prism groove.

In this embodiment, the strip-shaped step-shaped microstructures 72 on the same film unit 701 or 702 have a predetermined distance therebetween. The portion of the first optical surface 703 located in the spaced area is parallel to the lower surface 709 of the substrate 700, which is the second optical surface 704, and may also be the first light-transmitting portion 720 of the first optical surface 703.

Alternatively, the elongated terrace-shaped microstructures 72 on the same film- layer unit 701 or 702 may be closely adjacent to each other without a gap.

Compared with the prior art, the optical film layer structure 5, the backlight module 4, the display device 3 and the electronic equipment 1 provided by the application realize the bidirectional penetration of backlight and detection light on the premise of no hole opening through the reasonable shape of the microstructure 52, and are beneficial to realizing the sensing under the screen on the premise of not influencing the display effect, thereby further improving the screen occupation ratio of the electronic equipment 1 and improving the visual perception of the electronic equipment.

In the description herein, references to the description of the terms "one embodiment," "certain embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the purpose of illustrating the preferred embodiments of the present application and is not to be construed as limiting the present application, and any modifications, equivalents and improvements made within the spirit and principle of the present application are intended to be included within the scope of the present application.

Claims (15)

1. An optical film structure for converging backlight light and transmitting detection light, characterized in that: the film comprises a first film unit and a second film unit, wherein each film unit comprises a substrate and a plurality of microstructures arranged on the substrate at intervals, the substrate comprises an upper surface and a lower surface which are opposite in parallel, the microstructures are arranged on the upper surface, each microstructure comprises a top surface back to the substrate, the top surface is at least parallel to the lower surface part of the substrate opposite to the top surface, and the propagation direction of at least one part of light penetrating through the film unit through the top surface is unchanged.

2. The optical film layer structure of claim 1, wherein: the film layer unit surface of the spacing part between the microstructures is at least parallel to the substrate lower surface part opposite to the film layer unit surface, the propagation direction of at least one part of light rays penetrating through the film layer unit surface of the spacing part between the microstructures is unchanged, and the ratio range of the film layer unit surface area of the spacing part between the microstructures to the top surface area is more than or equal to one fourth and less than one.

3. The optical film layer structure of claim 1, wherein: the microstructure comprises a side surface which is not parallel to the lower surface part of the opposite substrate, the propagation direction of at least one part of light penetrating through the film layer unit through the side surface is changed, and the angle range of an included angle between the side surface and the upper surface of the substrate is more than or equal to 40 degrees and less than or equal to 90 degrees.

4. The optical film layer structure of claim 1, wherein: the microstructures on the first film unit and the second film unit are long-strip terraces or long-strip cuboids extending along a specific direction, wherein the first film unit and the second film unit are sequentially arranged along a light path, and the extension directions of the microstructures on the first film unit and the second film unit are mutually perpendicular.

5. The optical film layer structure of claim 1, wherein: the microstructure is double-deck step shape, and it is protruding to include the first arch that sets up on the basement and the second that forms at first protruding top surface, first arch is long-strip-shaped terraced platform or the rectangular shape cuboid that extends along specific direction, the protruding upright long-strip-shaped triangular prism that forms on first bellied top surface of second, long-strip-shaped triangular prism extends along the direction the same with long-strip-shaped terraced platform, via two disconnected planar regions that lie in long-strip-shaped triangular prism both sides respectively on the top surface see through the direction of propagation of at least some light of rete unit is unchangeable.

6. The optical film layer structure of claim 1, wherein: the sum of the areas of the top surfaces of the microstructures on the first film layer unit or the second film layer unit and the film layer unit surface of the spacing part between the microstructures accounts for more than or equal to 63% of the area of the lower surface of the substrate respectively, and the product of the two is more than or equal to 40%.

7. The optical film layer structure of claim 1, wherein: the top surfaces of the microstructures, the lower surface of the substrate and the film layer unit surfaces of the interval parts among the microstructures are all planes.

8. A backlight module is characterized in that: the optical film structure is used for providing backlight light to a display panel and transmitting detection light emitted and/or reflected by an external object to a sensing module, the sensing module is used for performing corresponding sensing according to the detection light, the backlight module comprises the optical film structure according to any one of claims 1 to 7, and the wavelength of the detection light is different from that of the backlight light.

9. The backlight module of claim 8, wherein: the optical film layer structure and the diffusion sheet are sequentially arranged along a light path, and the diffusion sheet comprises a base material and a rough glass-shaped microstructure formed on the base material; or

The diffusion sheet comprises a base material and diffusion particles doped on the base material, wherein the diffusion particles are made of a material which can transmit infrared light or near infrared light and reflect visible light, and the average size of the diffusion particles is in the range of 380 nanometers to 780 nanometers; or

The diffusion sheet is a film layer with a nano porous structure, and a plurality of nano-scale pores are formed in the film layer; or

The diffusion sheet is a quantum dot film layer arranged on the light emitting surface of the light guide plate, the quantum dot film layer contains quantum dot materials, the quantum dot materials absorb blue backlight light and convert the blue backlight light into green backlight light and red backlight light respectively, the backlight module further comprises a backlight source used for providing backlight light, and the backlight source is a blue light emitting source.

10. The backlight module of claim 9, wherein: further comprising:

the light guide plate comprises a light-emitting surface and a bottom surface opposite to the light-emitting surface;

and the reflecting sheet is arranged on one side of the bottom surface and used for reflecting the backlight light transmitted out of the bottom surface of the light guide plate, wherein the reflecting sheet is made of a material which can transmit infrared light or near infrared light and reflect visible light.

11. A display device, characterized in that: the display device comprises a display panel and a backlight module, wherein the display panel is used for displaying pictures, and the backlight module is used for providing backlight light to the display panel, and the backlight module is the backlight module of any one of the claims 8-10.

12. An electronic device, characterized in that: comprising the display device of claim 11 and a sensor module disposed at least partially under the display device, the sensor module receiving the detection light reflected or/and emitted from the external object through the display device to perform corresponding sensing.

13. The electronic device of claim 12, wherein: the sensing module comprises a receiving unit, the receiving unit is arranged below the backlight module, and receives the detection light through the display panel and the backlight module so as to execute corresponding sensing.

14. The electronic device of claim 13, wherein: the sensing module further comprises an emitting unit, the emitting unit is used for emitting the detection light to the external object, and the receiving unit is arranged below the backlight module or beside the display device and is positioned in a non-display area.

15. The electronic device of claim 12, wherein: the sensing module is used for executing one or more of fingerprint sensing, three-dimensional face sensing and living body sensing.

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