CN210155476U - Optical film layer structure, backlight module, display device and electronic equipment - Google Patents

Abstract

The application provides an optical film layer structure, which is used for gathering backlight light and transmitting detection light and comprises one or more film layer units. 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. The surface of the film layer unit in the interval area between the microstructures is at least parallel to the part of the lower surface of the substrate opposite to the surface of the film layer unit, and the propagation direction of at least one part of light penetrating through the film layer unit through the surface of the film layer unit in the interval area between the microstructures is unchanged. The outer surface of the microstructure is not parallel to the lower surface part of the substrate opposite to the outer surface of the microstructure, and the propagation direction of at least one part of light rays passing through the film layer unit through the outer surface of the microstructure is changed.

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 unit comprises one or more film units, 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, the surfaces of the film units in the spacing areas among the microstructures are at least parallel to the lower surface part of the substrate opposite to the film units, the propagation direction of at least one part of light penetrating through the film units through the surfaces of the film units in the spacing areas among the microstructures is unchanged, the outer surfaces of the microstructures are not parallel to the lower surface part of the substrate opposite to the outer surfaces of the microstructures, and the propagation direction of at least one part of light penetrating through the film units through the outer surfaces of the microstructures is changed.

In some embodiments, the lower surface of the substrate is entirely planar.

In some embodiments, the outer surface of the microstructure comprises a bevel that is oblique to the lower surface of the substrate.

In some embodiments, the optical film structure includes a first film unit and a second film unit, where the microstructures on the first film unit and the second film unit are elongated protrusions extending along a specific direction, the first film unit and the second film unit are sequentially arranged along an optical path, and extending directions of the microstructures are perpendicular to each other.

In some embodiments, the elongated protrusion is an elongated triangular prism standing upright on the upper surface of the substrate.

In some embodiments, the outer surface of the microstructure includes a pair of side surfaces extending along the length direction thereof, the pair of side surfaces intersect above the substrate to form one of the edges of the elongated triangular prism, and the pair of side surfaces intersect with the upper surface of the substrate to form the other two edges of the elongated triangular prism.

In some embodiments, the optical film structure includes a film unit, and the microstructure is a plurality of bumps arranged in an array on the substrate.

In certain embodiments, the microstructures are conical or pyramidal.

In some embodiments, the lower surface of the substrate, the outer surfaces of the microstructures, and the surfaces of the film layer units located at the intervals between the microstructures are boundary surfaces when light passes through the film layer units.

In certain embodiments, the microstructures are made of the same or different material as the substrate.

In some embodiments, when the material of the microstructure is different from the material of the substrate, the material of the microstructure has a refractive index that is the same as or similar to the refractive index of the material of the substrate, such that the light rays propagate approximately straight lines when passing through the interface of the microstructure and the substrate.

In some embodiments, a light diffusion layer for diffusing light is disposed on the lower surface of the substrate of the film layer unit.

The application provides a backlight module, which 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 detection light is used for detecting or identifying biological characteristic information of an external object, and the backlight module comprises the optical film layer structure provided by the embodiment.

In some embodiments, the backlight module further comprises a diffusion sheet for diffusing backlight light, the optical film layer structure and the diffusion sheet are arranged in sequence along a light path, and the diffusion sheet is made by forming rough micro-structures in a ground glass shape on a substrate; or

The diffusion sheet is prepared by doping diffusion particles on a base material; 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 some embodiments, the diffusing particles are made of a material that transmits infrared or near-infrared light and reflects visible light.

In certain embodiments, the average size of the diffusion particles is in the range of 380 nanometers to 780 nanometers.

In some embodiments, the diffuser has a greater diffusion effect on the backlight light than on the detection light.

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.

In some embodiments, the backlight module is used for providing visible light and can transmit infrared light or near infrared light.

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 provided by the above embodiment.

In some embodiments, the display panel is a liquid crystal display panel.

The application provides an electronic device, which comprises the display device provided by the embodiment and a sensing module at least partially arranged below the display device. The sensing module receives the detection light reflected or/and emitted by the external object through the display device so as to execute 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 structural diagram of the sensing module in fig. 2 integrated with a memory and a processor.

Fig. 4 is a schematic diagram of an internal structure of an electronic device according to a second embodiment of the present application.

Fig. 5 is a schematic front view of the electronic device of fig. 4.

Fig. 6 is a schematic structural diagram of a display device according to a third embodiment of the present application.

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

Fig. 8 is a schematic structural diagram of a backlight module according to a fifth embodiment of the present application.

Fig. 9 is a schematic structural diagram of a backlight module according to a sixth embodiment of the present application.

Fig. 10 is a schematic structural diagram of a backlight module according to a seventh embodiment of the present application.

Fig. 11 is a schematic structural diagram of a backlight module according to an eighth embodiment of the present application.

Fig. 12 is a schematic structural diagram of an optical film structure provided in a ninth embodiment of the present application.

Fig. 13 is an optical path diagram of the light in fig. 12 when the light passes through the first light transmission part and the second light transmission part.

Fig. 14 is a schematic structural diagram of an optical film structure provided in a tenth embodiment of the present application.

Fig. 15 is a schematic structural diagram of an optical film structure provided in an eleventh embodiment of the present application.

Fig. 16 is a schematic structural diagram of an optical film structure provided in a twelfth embodiment of the present application.

Fig. 17 is a schematic structural diagram of an optical film structure provided in a thirteenth embodiment of the present application.

Fig. 18 is a schematic structural diagram of an optical film structure provided in a fourteenth embodiment of the present application.

Fig. 19 is a schematic structural diagram of an optical film structure provided in a fifteenth embodiment of the present application.

Fig. 20 is a schematic structural diagram of an optical film structure provided in a sixteenth embodiment of the present application.

Fig. 21 is a schematic structural diagram of an optical film layer structure according to a seventeenth embodiment of the present disclosure.

Fig. 22 is a schematic structural diagram of an optical film structure provided in an eighteenth embodiment of the present application.

Fig. 23 is a schematic structural diagram of an optical film structure provided in a nineteenth embodiment of the present application.

Fig. 24 is a schematic structural diagram of an optical film structure provided in a twentieth embodiment of the present application.

Fig. 25 is a schematic structural diagram of an optical film structure according to a twenty-first embodiment of the present disclosure.

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. In addition, the various specific processes and materials provided in the following description of the present application are only examples of implementing the technical solutions of the present application, but one of ordinary skill in the art should recognize that the technical solutions of the present application can also be implemented by other processes and/or other materials not described below.

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, as shown in fig. 3, 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 use.

As shown in fig. 4, a 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.

Further, it is understood that, as shown in fig. 5, the memory 22 and the processor 24 may be disposed at other positions inside the electronic device 2 independently from the sensing module 20.

As shown in fig. 6, a 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. 7, 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.

The stacking method of the light guide plate 42, the diffuser 46 and the optical film layer structure 5 is defined as a vertical direction, the first optical surface 503 comprises at least one first plane 5030 perpendicular to the vertical direction, and the second optical surface 504 comprises a second plane 5040 perpendicular to the vertical direction. Therefore, the first flat surface 5030 and the second flat surface 5040 are parallel to each other, and the first flat surface 5030 may serve as the first light-transmitting portion 520. The first flat 5030 can be opposite the second flat 5040, or can be offset from the second flat 5040. The second light-transmitting portion 522 includes an inclined surface 5220, the inclined surface 5220 is inclined between the first light-transmitting portion 520 and the second optical surface 504, and backlight light incident to the first film layer unit 501 is converged when exiting from the inclined surface 5220. The inclined surface 5220 is connected to the first plane 5030, and the included angle therebetween is an obtuse angle.

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 different from the material of the microstructures 52, the substrate 500 and the material of the microstructures 52 have similar refractive indices. 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 top surface of the step-like structure is the first plane of the first optical surface 503, i.e. the first light-transmitting portion 520. 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 surface of the step-shaped structure extends 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, and the microstructures 52 are closely arranged without space.

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.

Alternatively, in some embodiments, as shown in fig. 18, the microstructures 52 may be 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 in the spaced-apart regions is a plane parallel to the second optical surface 504 and can be used as one of the first planes 5030 of the first optical surface 503, where the first plane 5030 has a different vertical distance to the second plane 5040 than the first plane 5030 at the top of the microstructure 52.

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 are arranged up and down, so that a part of detection light mainly undergoes translation of the light position when passing through the first film layer unit 501 and the second film layer unit 502, the propagation direction is basically unchanged, and 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.

Alternatively, in some embodiments, as shown in FIG. 10, the optical film layer structure 5 may also be a single-layer film sheet structure, including only a single-piece film 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 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.

As shown in fig. 8, 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 upper diffuser 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.

The upper diffuser 461 and/or the lower diffuser 462 may be replaced by a light diffuser layer 505 (see fig. 9) formed on the second optical surface 504 of the first film layer unit 501, the second film layer unit 502, or the monolithic film layer unit 50. For example: as shown in fig. 8 and 9, a sixth 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 light diffusion layer 505 is formed on the second optical surface 504 of the first film layer unit 501 instead of the upper diffusion sheet 461.

As shown in fig. 10, a seventh 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 diffuser sheet 462 (see fig. 8) is replaced by a light diffuser layer 505 formed on the second optical surface 504 of the monolithic film layer unit 50. The upper diffusion sheet 461 is disposed at the light exit side of the single film layer unit 50.

Alternatively, as shown in fig. 11, an eighth 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.

It is to be understood that, in the above-described embodiment, the light diffusion layer 505 formed on the second optical surface 504 on the first film layer unit 501 may be omitted. In addition, when the optical film layer structure 5 is a single-layer film structure, the light diffusion layer 505 on the second optical surface 504 may also be omitted.

As shown in fig. 12, a ninth 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 transmission direction of at least part of detection light to be basically unchanged and the position of the detection light to translate when the detection light penetrates through, so that the requirements of increasing display brightness and sensing by arranging the sensing module 10 below a screen are met simultaneously.

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. 7) that emits backlight light. The second optical surface 504 is disposed near a light emitting surface 420 (see fig. 7) 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 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. 13, 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. Referring to the label in fig. 13, a portion of the detection light before entering from the first transparent portion 520 is O1, and a 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 transmission 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, and the accuracy of the obtained sensing data can be improved.

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 rectangular parallelepiped structures, and the top surfaces of the protruding structures may include surface portions substantially parallel to the lower surface of the substrate.

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.

Alternatively, the microstructures 52 and substrate 500 may also be two separate film layers bonded together by an adhesive. The adhesive may include, but is not limited to, a pressure sensitive adhesive or a uv curable adhesive.

As shown in fig. 14, a tenth embodiment of the present application provides an optical film structure 5 that can be used in the backlight module 4, which is substantially the same as the optical film structure 5 provided in the ninth embodiment, and the main differences are: in the ninth embodiment, the second optical surface 504 of the first film-layer unit 501 is a flat surface. Optionally, in this embodiment, a light diffusion layer 505 for diffusing light rays may be further disposed on the second optical surface 504 of the first film layer unit 501, instead of the diffusion sheet 46 (see fig. 7). The light diffusion layer 505 is a layer of rough texture like ground glass to diffuse incident backlight light. It is understood that the light diffusing layer 505 may be molded directly onto the second optical surface 504, or a coating may be applied to the second optical surface 504 and then molded into a rough texture in the form of a ground glass. The material of the light diffusion layer 505 may be different from the substrate 500 of the first film layer unit 501, and may be a material that can transmit infrared light or near infrared light and reflect visible light. The rough texture may be, for example, a plurality of small protrusions. The average size of the small protrusions can be in a visible light wavelength range of 380 nanometers (nm) to 760nm, so that the small protrusions can have a relatively obvious scattering effect on visible light and have relatively strong penetrability on infrared or near-infrared detection light with longer wavelength.

As shown in fig. 15, an eleventh embodiment of the present application provides an optical film structure 5 that can be used in the backlight module 4, which is substantially the same as the optical film structure 5 provided in the tenth embodiment, and the main differences are: in order to reduce scattering of the detection light reflected by an external object when the detection light passes through the light diffusion layer 505 of the first film layer unit 501, a sensing portion 506 having a flat surface is formed on the light diffusion layer 505 at a position corresponding to the detection light that needs to pass through the reflected detection light. The sensing portion 506 is disposed corresponding to a position of the sensing module 10 (see fig. 3) located below the backlight module 4 (see fig. 3). It is understood that, in other embodiments, the sensing portion 506 may also be a plurality of light holes penetrating through the light diffusion layer 505, so that part of the reflected detection light is not diffused when passing through the light holes, so as to facilitate subsequent sensing.

As shown in fig. 16, a twelfth embodiment of the present application provides an optical film structure 5 that can be used in the backlight module 4, which is substantially the same as the optical film structure 5 provided in the tenth embodiment, and the main differences are: the light diffusion layer 505 may also be a coating layer formed on the second optical surface 504 of the first film layer unit 501, and a plurality of diffusion particles 507 for diffusing light rays are doped in the coating layer. It is understood that the diffusion particles 507 may be made of a material that is transparent to infrared or near infrared light and reflects visible light. The average size of the diffusion particles 507 is within a visible light wavelength range of 380nm (Nanometer) to 760nm, so that the diffusion particles can have a significant scattering effect on visible light and have strong permeability to infrared or near-infrared detection light with longer wavelength.

As shown in fig. 17, a thirteenth 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 ninth embodiment, except that: 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.

In the present embodiment, the elongated terrace-shaped microstructures 62 are closely connected to each other without a space therebetween. The second optical surface 604 comprises a lower surface 609 of the substrate 600. The first light transmissive portion 620 of the first optical surface 603 comprises a top surface 621 of an elongated terrace. The second light-transmissive portion 622 of the first optical surface 603 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.

As shown in fig. 18, a fourteenth embodiment of the present application provides an optical film structure 6 that can be used in the backlight module 4, which is substantially the same as the optical film structure 6 provided in the thirteenth embodiment, and the main differences are: 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. A portion of the first optical surface 603 located in the spaced area remains substantially parallel to the lower surface 609 of the substrate 600 as the second optical surface 604, and may also serve as a first light-transmitting portion 620 of the first optical surface 603. Therefore, in this embodiment, the first light-transmitting portion 620 includes a top surface 621 of the elongated terrace and a portion of the first optical surface 603 in the spaced area between the adjacent microstructures 62. The portion of the first optical surface 603 can be a portion of the substrate 600 not covered by the microstructures 62 or an outer surface of the layer of microstructure 62 material covered in the spaced-apart regions.

As shown in fig. 19, a fifteenth embodiment of the present application provides an optical film structure 6 that can be used in the backlight module 4, which is substantially the same as the optical film structure 6 provided in the fourteenth embodiment, and the main differences are: the elongated microstructures 62 may also be elongated triangular prisms. The elongated triangular prism is erected on the upper surface 608 of the substrate 600. The cross section of the strip-shaped triangular prism shape along the direction perpendicular to the edges is in a regular triangle shape. The elongated prism shape includes a pair of side surfaces 624 extending along the length thereof. The pair of side surfaces 624 are respectively inclined to the upper surface 608 and/or the lower surface 609 of the substrate 600, and form an obtuse angle with the upper surface 608 of the substrate 600. The pair of side surfaces 624 intersect above the substrate 600 to form one of the edges of the elongated triangular prism. The pair of side surfaces 624 intersect the upper surface 608 of the substrate 600 to form the other two edges of the elongated triangular prism. The elongated triangular prism-shaped microstructures 62 on the same film unit 601 or 602 have a predetermined distance therebetween. Portions of the first optical surface 603 located in the spaced regions between adjacent microstructures 62 remain substantially parallel to the lower surface 609 of the substrate 600 as the second optical surface 604. Thus, in this embodiment, first light-transmissive portion 620 of first optical surface 603 includes portions of first optical surface 603 that are located in spaced areas between adjacent microstructures 62. The second light-transmitting portion 622 includes a pair of side surfaces 624 of the elongated triangular prism.

As shown in fig. 20, a sixteenth 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 thirteenth embodiment, except that: 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 the present embodiment, the elongated terrace-shaped microstructures 72 on the same film- layer unit 701 or 702 are closely adjacent to each other without a gap. Alternatively, the elongated terrace-shaped microstructures 72 on the same film unit 701 or 702 may have a predetermined distance therebetween, and the overall layout thereof is shown in fig. 18 and will not be described herein again. 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.

As shown in fig. 21, a seventeenth embodiment of the present application provides an optical film structure 8 that can be used in the backlight module 4, and is substantially the same as the optical film structure 5 provided in the ninth embodiment, and the main differences are as follows: the optical film-layer structure 8 comprises a film-layer unit 80. The substrate 800 of the film layer unit 80 is provided with a plurality of the microstructures 82 arranged in an array.

In this embodiment, each of the microstructures 82 is a rectangular parallelepiped bump, and includes a top surface 821 facing away from the substrate 800 and a side surface 823 extending from a periphery of the top surface 821. The top surface 821 is parallel to the lower surface 809 of the substrate 800. The side surfaces 823 are perpendicular to the top surface 821. The top surface 821 is rectangular and is a continuously extending planar area. The first light-transmissive portion 820 of the first optical surface 803 includes a top surface 821 of the cuboid bump. The second light-transmitting portion 822 of the first optical surface 803 includes a side surface 823 of the rectangular parallelepiped bump.

It will be appreciated that due to the spacing arrangement between the microstructures 82, the portion of the first optical surface 803 located in the spaced area, for example: the portion of the substrate 800 not covered by the microstructures 82 or the outer surface of the layer of microstructure 82 material covering the spaced areas is parallel to the lower surface 809 of the substrate 800, which is the second optical surface 804. Accordingly, the first light-transmitting portion 820 further includes a portion of the first optical surface 803 on the film layer unit 80 in the spaced area.

It is understood that the second optical surface 804 of the film layer unit 80 may also be provided with the light diffusion layer (not shown) for diffusing backlight light.

Alternatively, in other embodiments, the optical film layer structure 8 may also include two or more film layer units 80 with similar structures. The specific situation depends on the light-gathering capability of the film unit 80 and the required backlight brightness requirement of the lcd panel 30, and is not limited herein. The positions of the microstructures 82 or the positions of the spaces between the microstructures 82 on different film-layer units 80 are staggered from each other. That is, the microstructures 82 on the lower film unit 80 are aligned with the spaced positions on the upper film unit 80, so that the backlight light can penetrate the first film unit 80 through the first light-transmitting portion 820 and then penetrate the second film unit 80 through the second light-transmitting portion 822 with a high probability, thereby facilitating the uniformity of backlight emission.

As shown in fig. 22, an eighteenth embodiment of the present application provides an optical film structure 9 that can be used in the backlight module 4, and is substantially the same as the optical film structure 8 provided in the seventeenth embodiment, and the main differences are: the first light-transmissive portion 920 on each microstructure 92 includes a multiply connected region. The multi-connection area is formed by removing at least a part of the area in the area enclosed by the simple closed curve, such as: an annular region.

In this embodiment, the plurality of microstructures 92 are arranged in an array on the substrate 900. Each of the microstructures 92 has a double-step shape, and includes a first protrusion 923 disposed on the upper surface 908 of the substrate 900 and a second protrusion 924 formed on a top surface of the first protrusion 923. The first protrusion 923 may have a truncated pyramid shape. The second protrusions 924 may be right pyramids formed on the top surfaces of the first protrusions 923. The top surface of the first protrusion 923 surrounds the second protrusion 924 to form a multi-communication area in the shape of a ring. The first light-transmitting portion 920 on the microstructure 92 is an annular multi-communication region. The top surfaces of the first protrusions 923 are parallel to the upper surface 908 and the lower surface 909 of the substrate 900. The lower surface 909 of the substrate 900 is the second optical surface 904 of the film-layer unit 90. Therefore, in this embodiment, the first light-transmitting portion 920 includes a multi-connection region surrounding the second protrusion 924 on the top surface of the first protrusion 923, and the multi-connection region is an annular region. The second light-transmitting portion 922 includes a side surface of the second protrusion 924 and a side surface of the first protrusion 923. The side of the second protrusion 924 and the side of the first protrusion 923 form an obtuse angle with the top surface of the first protrusion 923.

Alternatively, the first protrusions 923 of the microstructure 92 may also have a truncated cone shape. The second projection 924 may also be conical. Or, the first protrusion 923 and the second protrusion 924 are respectively any combination of a frustum, a circular truncated cone, a pyramid and a cone.

Alternatively, the number of steps of the microstructure 92 may be two or more. The top surface of each layer of protrusions substantially parallel to the second optical surface 904 serves as the first light-transmitting portion 920 of the microstructure 92, while the side surfaces of the protruding structures serve as the second light-transmitting portions 922 of the microstructure 92.

Alternatively, the second protrusions 924 may be replaced by groove structures formed on the top surfaces of the first protrusions 923, the groove structures having the same shape as the second protrusions 924. For example, the groove structure is a pyramid or a cone-shaped groove.

In the present embodiment, the microstructures 92 are closely adjacent to each other without any space therebetween. Alternatively, in other embodiments, the microstructures 92 are arranged at a predetermined interval from each other. The portion of the first optical surface 903 located in the spaced area remains parallel to the lower surface 909 that is the second optical surface 904, and may also serve as the first light-transmitting portion 920 of the first optical surface 903.

As shown in fig. 23, a nineteenth embodiment of the present application provides an optical film structure 9 that can be used in the backlight module 4, which is substantially the same as the optical film structure 9 provided in the eighteenth embodiment, and the main differences are: the microstructure 92 is a plurality of single-layer protrusions 923 arrayed on the substrate 900. The single-layer protrusion 923 may have a shape of a terrace or a truncated cone. The single layer protrusion 923 is disposed on the upper surface 908 of the substrate 900. The single-layer protrusion 923 includes a top surface 921 and a side surface 925 extending from the periphery of the top surface 921. The top surfaces 921 of the single-layer protrusions 923 are parallel to the upper and lower surfaces 908, 909 of the substrate 900. The side surfaces 925 of the single-layer protrusions 923 are inclined to the top surface 921 and the upper surface 908 of the substrate 900. The side surfaces 925 of the single-layer protrusions 923 respectively form obtuse angles with the top surface 921 and the upper surface 908 of the substrate 900. In the present embodiment, the single-layered protrusions 923 in the shape of the terraces or frustums are closely adjacent to each other without a space therebetween. The lower surface 909 of the substrate 900 is the second optical surface 904. The first light-transmitting portion 920 includes a top surface 921 of the single-layer protrusion 923. The second light-transmitting portion 922 includes a side surface 925 of the single-layer protrusion 923.

As shown in fig. 24, a twentieth embodiment of the present application provides an optical film structure 9 that can be used in the backlight module 4, and is substantially the same as the optical film structure 9 provided in the nineteenth embodiment, with the main differences that: the single-layer bulges 923 arranged in an array form a preset interval. The portion of the first optical surface 903 located within the spaced area, for example: the portion of the substrate 900 not covered by the single layer protrusions 923 or the outer surface of the layer of single layer protrusions 923 material in the spaced areas is parallel to the lower surface 909 of the substrate 900 that is the second optical surface 904. Accordingly, the first light-transmitting portion 920 further includes a portion of the first optical surface 903 on the film layer unit 90 located in the spaced area.

As shown in fig. 25, a twenty-first embodiment of the present application provides an optical film structure 9 that can be used in the backlight module 4, which is substantially the same as the optical film structure 9 provided in the twentieth embodiment, and the main differences are: the single-layered protrusions 923 arranged in an array with a predetermined interval therebetween are conical or pyramidal in shape, and do not have top surfaces parallel to the upper surface 908 and/or the lower surface 909 of the base 900. Thus, the first light-transmitting portion 920 is a portion of the first optical surface 903 on the film layer unit 90 located in the spaced area, such as: the portion of the substrate 900 not covered by the single layer projections 923 is the outer surface of the layer of single layer projections 923 material that is covered in the spaced areas.

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 (25)

1. An optical film structure for converging backlight light and transmitting detection light, characterized in that: the film unit comprises one or more film units, 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, the surfaces of the film units in the spacing areas among the microstructures are at least parallel to the lower surface part of the substrate opposite to the film units, the propagation direction of at least one part of light penetrating through the film units through the surfaces of the film units in the spacing areas among the microstructures is unchanged, the outer surfaces of the microstructures are not parallel to the lower surface part of the substrate opposite to the outer surfaces of the microstructures, and the propagation direction of at least one part of light penetrating through the film units through the outer surfaces of the microstructures is changed.

2. The optical film layer structure of claim 1, wherein: the lower surface of the substrate is a plane as a whole.

3. The optical film layer structure of claim 1, wherein: the outer surface of the microstructure comprises a slope, and the slope is inclined to the lower surface of the substrate.

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

5. The optical film layer structure of claim 4, wherein: the strip-shaped protrusion is a strip-shaped triangular prism which is upright on the upper surface of the substrate.

6. The optical film layer structure of claim 5, wherein: the outer surface of the microstructure comprises a pair of side surfaces extending along the length direction of the microstructure, the side surfaces are intersected above the substrate to form one edge of the long-strip-shaped triangular prism, and the side surfaces are respectively intersected with the upper surface of the substrate to form the other two edges of the long-strip-shaped triangular prism.

7. The optical film layer structure of claim 1, wherein: the optical film layer structure comprises a film layer unit, and the microstructure is a plurality of bumps arranged in an array on the substrate.

8. The optical film layer structure of claim 7, wherein: the microstructure is conical or pyramidal.

9. The optical film layer structure of any of claims 1-8, wherein: the lower surface of the substrate, the outer surfaces of the microstructures and the surfaces of the film layer units positioned at the interval parts among the microstructures are boundary surfaces when light rays penetrate through the film layer units.

10. The optical film layer structure of any of claims 1-8, wherein: the microstructures are made of the same or different material as the substrate.

11. The optical film layer structure of claim 10, wherein: when the material of the microstructure is different from that of the substrate, the material refractive index of the microstructure is the same as or similar to that of the substrate, so that the light rays are approximately linearly propagated when passing through the interface surface of the microstructure and the substrate.

12. The optical film layer structure of claim 1, wherein: and a light diffusion layer for diffusing light is arranged on the lower surface of the substrate of the film layer unit.

13. A backlight module is characterized in that: the optical film structure for providing backlight light to a display panel and transmitting detection light emitted and/or reflected by an external object to a sensing module, wherein the detection light is used for detecting or identifying biological characteristic information of the external object, and the backlight module comprises the optical film structure as claimed in any one of claims 1 to 12.

14. The backlight module of claim 13, wherein: the backlight module further comprises a diffusion sheet, wherein the diffusion sheet is used for diffusing backlight light rays, the optical film layer structure and the diffusion sheet are sequentially arranged along a light path, and the diffusion sheet is made by forming rough micro structures in a ground glass shape on a base material; or

The diffusion sheet is prepared by doping diffusion particles on a base material; 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.

15. The backlight module of claim 14, wherein: the diffusion particles are made of a material that transmits infrared or near-infrared light and reflects visible light.

16. The backlight module of claim 14, wherein: the average size of the diffusion particles is in the range of 380nm to 780 nm.

17. The backlight module of claim 14, wherein: the diffusion effect of the diffusion sheet on the backlight light is larger than that of the diffusion sheet on the detection light.

18. The backlight module of claim 17, 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.

19. The backlight module of claim 17, wherein: the backlight module is used for providing visible light and can transmit infrared light or near infrared light.

20. A display device, characterized in that: comprising a display panel for displaying a picture and a backlight module for providing backlight light to the display panel, wherein the backlight module is according to any of the above claims 13-19.

21. The display device of claim 20, wherein: the display panel is a liquid crystal display panel.

22. An electronic device, characterized in that: comprising the display device of claim 20 or 21 and a sensing module disposed at least partially under the display device, the sensing module receiving the detection light reflected or/and emitted from the external object through the display device to perform corresponding sensing.

23. The electronic device of claim 22, 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.

24. The electronic device of claim 23, 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.

25. The electronic device of claim 23, 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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