Patent Description:
The present invention relates to the field of display technologies, and in particular, to a laminated structure, a display panel, and an electronic device.

Recently, more electronic devices are provided with an optical fingerprint recognition module under a display panel, to facilitate unlocking of the electronic devices by users. Light needs to pass through laminated layers, such as a protective layer, a linear polarizing layer, and a quarter-wave plate, of the display panel before entering the optical fingerprint recognition module. However, because of differences in materials of the laminated layers of the display panel, the stability of light transmission in the display panel are affected, resulting in low stability of the light intensity of light entering the optical fingerprint recognition module, and reducing the recognition precision of the optical fingerprint recognition module. The <CIT> refers to a circular polarizer, a touch panel and a display device. <CIT>, <CIT> and <CIT> also represent prior art useful for understanding the invention.

A technical problem to be resolved by embodiments of this application is about a laminated structure, a display panel, and an electronic device that can improve the stability of light transmission.

To achieve the foregoing objective, implementations of this application adopt the following technical solutions:.

According to a first aspect, an implementation of this application provides a laminated structure, including a protective layer, a linear polarizing layer, and a quarter-wave plate that are laminated in sequence. The protective layer is used to polarize light to form linearly polarized light. An angle between an absorption axis of the protective layer and an absorption axis of the linear polarizing layer is zero degrees. An angle between the absorption axis of the linear polarizing layer and an absorption axis of the quarter-wave plate is <NUM> degrees.

In this implementation, the angle between the absorption axis of the linear polarizing layer and the absorption axis of the protective layer is zero degrees, and there is no difference between a direction of the absorption axis of the protective layer and a direction of the absorption axis of the linear polarizing layer. Therefore, a luminous flux of light passing through the protective layer is roughly the same as that of light passing through the linear polarizing layer. In other words, the light intensity of the light passing through the protective layer is consistent with that of the light passing through the linear polarizing layer. In this way, the light loss during light transmission in the laminated structure can be reduced, and the stability of light transmission in the laminated structure can be improved, to stabilize the light intensity of light passing through the laminated structure, and improve the stability of light entering an optical fingerprint recognition module, thereby improving recognition precision of the optical fingerprint recognition module.

In a possible implementation, the laminated structure further includes a reinforcing layer, and the reinforcing layer is arranged between the protective layer and the linear polarizing layer, and used to protect the laminated structure and enhance the strength of the laminated structure.

In a possible implementation, the material strength of the reinforcing layer is greater than that of the protective layer.

In a possible implementation, the reinforcing layer is made of an isotropic material, to reduce the light loss during light transmission in the laminated structure, and enhance the stability of light transmission.

In a possible implementation, the linear polarizing layer is fixed to the reinforcing layer through an optical adhesive layer, to improve the bonding strength between the linear polarizing layer and the reinforcing layer.

In a possible implementation, the optical adhesive layer is made of an isotropic material, to further reduce the light loss during light transmission in the laminated structure, and enhance the stability of light transmission.

In a possible implementation, the reinforcing layer is a glass cover plate, to enhance the strength and protection performance of the laminated structure; and the protective layer is a film layer attached to one side of the reinforcing layer away from the linear polarizing layer, to prevent the reinforcing layer from being scratched and worn.

In a possible implementation, the reinforcing layer is used to polarize light to form linearly polarized light. An angle between an absorption axis of the reinforcing layer and the absorption axis of the linear polarizing layer is zero degrees. The reinforcing layer is set as a laminated layer in a direction consistent with the direction of the absorption axis of the linear polarizing layer, so that the optical performance of the reinforcing layer, the protective layer, and the linear polarizing layer can be matched, and the light intensity of light passing through the protective layer is consistent with that of light passing through the reinforcing layer and the linear polarizing layer, thereby enhancing the stability of light transmission.

In a possible implementation, the protective layer is a cover plate, and the protective layer is made of a material including one of ceramic and plastic, helping reduce a thickness of the laminated structure while increasing the strength of the protective layer.

In a possible implementation, the protective layer is made of materials including polyethylene terephthalate plastic and thermoplastic polyurethane elastomer rubber.

According to a second aspect, this application further provides a display panel, applied to an electronic device with an optical fingerprint recognition module. The display panel includes a functional substrate and the foregoing laminated structure that are laminated. The functional substrate is located on one side of a quarter-wave plate away from a protective layer, and the functional substrate has a light-transmitting area, to allow light emitted from the quarter-wave plate to enter the optical fingerprint recognition module through the light-transmitting area.

In this implementation, an angle between an absorption axis of the protective layer located on an outermost side of the display panel and an absorption axis of a linear polarizing layer is zero degrees, and there is no difference between a direction of the absorption axis of the protective layer and a direction of the absorption axis of the linear polarizing layer. Therefore, a luminous flux of light passing through the protective layer is roughly the same as that of light passing through the linear polarizing layer. In other words, the light intensity of light passing through the protective layer is consistent with that of light passing through the linear polarizing layer. In this way, the light loss during light transmission in the display panel can be reduced, and the stability of light transmission in the display panel can be improved, to stabilize the light intensity of light entering the optical fingerprint recognition module through the light-transmitting area of the functional substrate, and improve the stability of light entering the optical fingerprint recognition module, thereby improving the recognition precision of the optical fingerprint recognition module.

Further, the linearly polarized light passing through the protective layer becomes circularly polarized light passing through the linear polarizing layer and the quarter-wave plate. Part of the circularly polarized light is reflected into reversely polarized light due to a reflection structure in the display panel (such as a metal part in the functional substrate or an interface between adjacent laminated layers). The reversely polarized light is further rotated by <NUM> degrees after being incident to the quarter-wave plate to become linearly polarized light perpendicular to the direction of the absorption axis of the linear polarizing layer. Therefore, reflected light reflected by the reflection structure in the display panel can be effectively eliminated, thereby improving display and visual effects of the display panel.

In a possible implementation, the functional substrate includes a first light-transmitting layer, a plurality of reflection units, and a second light-transmitting layer. The plurality of reflection units are spaced on the first light-transmitting layer, the second light-transmitting layer covers the reflection units and the first light-transmitting layer, and the second light-transmitting layer is located between the quarter-wave plate and the first light-transmitting layer. Because the first light-transmitting layer and the second light-transmitting layer are arranged around the reflection units, an impact force when the laminated structure is collided can be buffered, which is beneficial to prolong life of the laminated structure.

In a possible implementation, both the first light-transmitting layer and the second light-transmitting layer are made of isotropic materials, to further reduce the light loss during light transmission in the laminated structure, and enhance the stability of the light intensity of light transmitting through the laminated structure, thereby improving the recognition precision of the optical fingerprint recognition module.

In a possible implementation, the first light-transmitting layer and the second light-transmitting layer are made of resin.

In a possible implementation, the reflection units are configured to emit light. When a finger touches one side of the protective layer away from the linear polarizing layer, or when a finger is at a specific distance from one side of the protective layer away from the linear polarizing layer, the light emitted by the reflection units can be reflected by the finger and enter the optical fingerprint recognition module through the light-transmitting area, thereby completing an optical fingerprint recognition function.

In a possible implementation, the display panel further includes a touch layer, arranged between the functional substrate and the quarter-wave plate.

According to a third aspect, an implementation of this application further provides an electronic device, including the foregoing laminated structure and an optical fingerprint recognition module. The optical fingerprint recognition module is located on one side of a functional substrate away from a protective layer, and configured to receive light passing through a light-transmitting area of the functional substrate.

In this implementation, an angle between an absorption axis of the protective layer located on an outermost side of the display panel and an absorption axis of a linear polarizing layer is zero degrees, and there is no difference between a direction of the absorption axis of the protective layer and a direction of the absorption axis of the linear polarizing layer. Therefore, a luminous flux of light passing through the protective layer is roughly the same as that of light passing through the linear polarizing layer. In other words, the light intensity of the light passing through the protective layer is consistent with that of the light passing through the linear polarizing layer. In this way, the light loss during light transmission in the display panel can be reduced, and the stability of light transmission in the display panel can be improved, to stabilize the light intensity of light entering the optical fingerprint recognition module through the light-transmitting area of the functional substrate, and improve the stability of light entering the optical fingerprint recognition module, thereby improving the recognition precision of the optical fingerprint recognition module.

According to a fourth aspect, not within the scope of the claimed invention, an implementation of this application further provides a method for preparing a laminated structure, including the following steps: providing a quarter-wave plate, a linear polarizing layer, and a protective layer; attaching the linear polarizing layer to the quarter-wave plate, and arranging the protective layer on one side of the linear polarizing layer away from the quarter-wave plate, so that the protective layer, the linear polarizing layer, and the quarter-wave plate are laminated. The protective layer is used to polarize light to form linearly polarized light. An angle between an absorption axis of the protective layer and an absorption axis of the linear polarizing layer is zero degrees. An angle between the absorption axis of the linear polarizing layer and an absorption axis of the quarter-wave plate is <NUM> degrees.

In a possible implementation, the arranging the protective layer on one side of the linear polarizing layer away from the quarter-wave plate includes: arranging a reinforcing layer on one side of the linear polarizing layer away from the quarter-wave plate, and arranging the protective layer on one side of the reinforcing layer away from the linear polarizing layer.

In a possible implementation, the arranging a reinforcing layer on one side of the linear polarizing layer away from the quarter-wave plate includes: fixing the reinforcing layer on the linear polarizing layer through an optical adhesive layer.

It should be understood that, the descriptions of technical features, technical solutions, beneficial effects, or similar expressions in this application are not intended to imply that all the features and advantages can be achieved in any single embodiment. On the contrary, it may be understood that the description of features or beneficial effects means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. In addition, the technical features, technical solutions, and beneficial effects described in this embodiment can also be combined in any appropriate manner. A person skilled in the art can understand that the embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in a specific embodiment that does not embody all embodiments.

<FIG> is a schematic diagram of a partial structure of an electronic device according to a first implementation. The electronic device <NUM> includes a display panel <NUM> and an optical fingerprint recognition module <NUM> that are laminated. The display panel <NUM> is located on a light entrance side of the optical fingerprint recognition module <NUM>, and is configured to display an image. The optical fingerprint recognition module <NUM> is configured to receive light transmitting through the display panel <NUM> to implement a fingerprint recognition function. The electronic device <NUM> may be any electronic device such as a smartphone, a smart watch, a tablet computer, a personal digital assistant (personal digital assistant, PDA for short), a point of sales (point of sales, POS for short), an on-board computer, a desktop computer, a laptop computer, or a smart TV. This is not limited in the embodiments of the present invention.

The display panel <NUM> includes a laminated structure <NUM> and a functional substrate <NUM> that are laminated. The functional substrate <NUM> is located between the laminated structure <NUM> and the optical fingerprint recognition module <NUM>. The functional substrate <NUM> has a light-transmitting area <NUM>, to allow light to enter the optical fingerprint recognition module <NUM> through the light-transmitting area <NUM>.

Specifically, the laminated structure <NUM> includes a quarter-wave plate (quarter-wave plate, QWP for short) <NUM>, a linear polarizing layer <NUM>, and a protective layer <NUM>. The functional substrate <NUM> is located between the optical fingerprint recognition module <NUM> and the quarter-wave plate <NUM>. The quarter-wave plate <NUM> can make ordinary light (o light) and extraordinary light (e light) equal to π/<NUM> or an odd multiple thereof. The quarter-wave plate <NUM> is sandwiched between the functional substrate <NUM> and the linear polarizing layer <NUM>. The protective layer <NUM> is arranged on one side of the linear polarizing layer <NUM> away from the quarter-wave plate <NUM>. Both the protective layer <NUM> and the linear polarizing layer <NUM> can polarize light to form linearly polarized light. An angle between an absorption axis of the linear polarizing layer <NUM> and an absorption axis of the protective layer <NUM> is zero degrees. An angle between an absorption axis of the quarter-wave plate <NUM> and the absorption axis of the linear polarizing layer <NUM> is <NUM> degrees. An angle between the absorption axis of the protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

In this implementation, in the linear polarizing layer <NUM>, light parallel to the absorption axis of the linear polarizing layer <NUM> may be absorbed by the linear polarizing layer <NUM>, and light perpendicular to the absorption axis of the linear polarizing layer <NUM> may be emitted through the linear polarizing layer <NUM>; and in the protective layer <NUM>, light parallel to the absorption axis of the protective layer <NUM> may be absorbed by the protective layer <NUM>, and light perpendicular to the absorption axis of the protective layer <NUM> may be emitted through the protective layer <NUM>.

Light is incident from the protective layer <NUM> in a direction opposite to the linear polarizing layer <NUM>, becomes linearly polarized light passing through the protective layer <NUM>, enters the linear polarizing layer <NUM>, and then is converted into circularly polarized light by the quarter-wave plate <NUM>. Part of the circularly polarized light enters the optical fingerprint recognition module <NUM> through the functional substrate <NUM>.

The protective layer <NUM> can polarize the light incident therein to form linearly polarized light, an angle between the absorption axis of the linear polarizing layer <NUM> and the absorption axis of the protective layer <NUM> is zero degrees, and there is no difference between a direction of the absorption axis of the protective layer <NUM> and a direction of the absorption axis of the linear polarizing layer <NUM>. Therefore, a luminous flux of light passing through the protective layer <NUM> is roughly the same as that of light passing through the linear polarizing layer <NUM>. In other words, the light intensity of the light passing through the protective layer <NUM> is consistent with that of the light passing through the linear polarizing layer <NUM>. In this way, the light loss during light transmission from the display panel <NUM> to the optical fingerprint recognition module <NUM> can be reduced, and the stability of light passing through the display panel <NUM> can be improved, to stabilize the light intensity of the light passing through the display panel <NUM>, and improve the stability of the light entering the optical fingerprint recognition module <NUM>, thereby improving the recognition precision of the optical fingerprint recognition module <NUM>.

The protective layer <NUM> is arranged on one side of the laminated structure <NUM> away from the optical fingerprint recognition module <NUM>, namely, an outermost side of the electronic device <NUM>. The laminated structure <NUM> further includes a reinforcing layer <NUM> arranged between the protective layer <NUM> and the linear polarizing layer <NUM>, and used to protect other laminated structures of the laminated structure <NUM> and enhance the strength of the laminated structure <NUM>. The reinforcing layer <NUM> is a glass cover plate and can enhance the strength of the laminated structure <NUM>. In this implementation, the material strength of the reinforcing layer <NUM> is greater than that of the protective layer <NUM>. The protective layer <NUM> is a film layer attached to one side of the reinforcing layer <NUM> away from the linear polarizing layer <NUM>, for example, a protective film on the outermost side of the display panel <NUM> of a smartphone, to prevent the reinforcing layer <NUM> from being scratched and worn.

The protective layer <NUM> is made of materials including polyethylene terephthalate (polyethylene terephthalate, PET for short) plastic and thermoplastic polyurethane (thermoplastic polyurethane, TUP for short) elastomer rubber. The reinforcing layer <NUM> is fixed to the linear polarizing layer <NUM> through an optical adhesive layer <NUM>. The reinforcing layer <NUM> is made of an isotropic material, to reduce the light loss during light transmission in the laminated structure <NUM>, and enhance the stability of light transmission. The isotropic refers to a property that physical and chemical properties of an object do not change due to different directions, namely, performance values of an object measured in different directions are completely the same, and is also known as homogeneity. The optical adhesive layer <NUM> is made of an isotropic material, to further reduce the light loss during light transmission in the laminated structure <NUM>, and enhance the stability of light transmission. It may be understood that, implementations of this application do not limit the material of the protective layer <NUM> and the material of the reinforcing layer <NUM>. For example, the reinforcing layer <NUM> may be made of plastic or ceramic.

In a possible implementation, the reinforcing layer <NUM> is used to polarize light to form linearly polarized light. An angle between an absorption axis of the reinforcing layer <NUM> and the absorption axis of the linear polarizing layer <NUM> is zero degrees. The reinforcing layer <NUM> is set as a laminated layer in a direction consistent with the direction of the absorption axis of the linear polarizing layer, so that the light intensity of light passing through the protective layer <NUM> is consistent with that of light passing through the reinforcing layer <NUM> and the linear polarizing layer <NUM>, and the optical performance of the reinforcing layer <NUM>, the protective layer <NUM> and the linear polarizing layer <NUM> can be matched, thereby enhancing the stability of light transmission in the laminated structure <NUM>.

In this implementation, the display panel <NUM> is a flexible display panel. The functional substrate <NUM> is an organic light-emitting diode (organic light-emitting diode, OLED for short) substrate. More specifically, the functional substrate <NUM> includes a first light-transmitting layer <NUM>, a plurality of reflection units <NUM>, and a second light-transmitting layer <NUM>. The reflection units <NUM> are configured to reflect light irradiated thereon. The reflection units <NUM> are also light-emitting units, configured to emit light. Light emitted by the reflection units <NUM> can be reflected by a finger and enter the optical fingerprint recognition module <NUM> through the light-transmitting area <NUM>, thereby implementing an optical fingerprint recognition function. The plurality of reflection units <NUM> are spaced on one side of the first light-transmitting layer <NUM>. The second light-transmitting layer <NUM> covers the reflection units <NUM> and the first light-transmitting layer <NUM>. The light-transmitting area <NUM> is formed between the adjacent reflection units <NUM>. The second light-transmitting layer <NUM> is located between the quarter-wave plate <NUM> and the first light-transmitting layer <NUM>. It may be understood that, the functional substrate <NUM> may also be a touch layer.

Because the reflection units <NUM> are surrounded by the first light-transmitting layer <NUM> and the second light-transmitting layer <NUM>, namely, the first light-transmitting layer <NUM> and the second light-transmitting layer <NUM> are arranged around the reflection units <NUM>, an impact force on the reflection units <NUM> when the laminated structure <NUM> is collided can be buffered, which is beneficial to prolong life of the display panel <NUM>. In this implementation, both the first light-transmitting layer <NUM> and the second light-transmitting layer <NUM> are made of isotropic materials, to reduce the light loss during light transmission in the display panel <NUM>, and enhance the stability of the light intensity when light passes through the display panel <NUM>. The reflection units <NUM> may be a circuit part such as a cathode and an anode.

In some implementations, the display panel <NUM> may be a touch display panel, and the display panel <NUM> further includes a touch layer, arranged between the functional substrate <NUM> and the quarter-wave plate <NUM>.

In some implementations, the protective layer <NUM> only needs to meet a condition that the angle between the absorption axis of the linear polarizing layer <NUM> and the absorption axis of the protective layer <NUM> is zero degrees.

It may be understood that, the laminated structure <NUM> includes the protective layer <NUM>, the linear polarizing layer <NUM>, and the quarter-wave plate <NUM> that are laminated in sequence. The protective layer <NUM> is used to polarize light to form the linearly polarized light, the angle between the absorption axis of the protective layer <NUM> and the absorption axis of the linear polarizing layer <NUM> is zero degrees, and the angle between the absorption axis of the linear polarizing layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

<FIG> is a light path of light incident to a laminated structure in the first implementation of this application.

The light is natural light. After light <NUM> is incident from one side of the protective layer <NUM> away from the reinforcing layer <NUM>, the protective layer <NUM> first polarizes the incident light to form linearly polarized light <NUM>.

The linearly polarized light <NUM> enters the linear polarizing layer <NUM> after passing through the reinforcing layer <NUM> and the optical adhesive layer <NUM>. Because the angle between the absorption axis of the linear polarizing layer <NUM> and the absorption axis of the protective layer <NUM> is zero degrees, the linearly polarized light <NUM> is still linearly polarized light passing through the linear polarizing layer <NUM>.

The linearly polarized light passing through the reinforcing layer <NUM>, the linearly polarized light passing through the optical adhesive layer <NUM>, and the linearly polarized light passing through the linear polarizing layer <NUM> are marked as linearly polarized light <NUM>, linearly polarized light <NUM>, and linearly polarized light <NUM> respectively. The linearly polarized light <NUM> is converted into circularly polarized light <NUM>, for example, right circularly polarized light shown in <FIG>, after passing through the quarter-wave plate <NUM>.

The circularly polarized light <NUM> enters the functional substrate <NUM>. Part of the circularly polarized light <NUM> is reflected by the reflection units <NUM> of the functional substrate <NUM> and becomes reversely polarized light <NUM>, for example, left circularly polarized light shown in <FIG>. The reversely polarized light <NUM> is emitted from the functional substrate <NUM> and enters the quarter-wave plate <NUM>. The reversely polarized light <NUM> is converted into linearly polarized light <NUM> after passing through the quarter-wave plate <NUM>. Obviously, a polarization angle of the linearly polarized light <NUM> is rotated by <NUM> degrees with respect to the linearly polarized light <NUM>. Because the linearly polarized light <NUM> is perpendicular to the absorption axis of the linear polarizing layer <NUM>, part of the linearly polarized light <NUM> cannot pass through the linear polarizing layer <NUM>, thereby reducing reflected light caused by the reflection units <NUM> in the laminated structure <NUM>. Part of the circularly polarized light <NUM> enters the optical fingerprint recognition module <NUM> through the light-transmitting area <NUM>.

<FIG> is a schematic diagram of absorption axes of laminated layers of the laminated structure in the first implementation of this application. The absorption axis of the protective layer <NUM> is a bidirectional absorption axis, the absorption axis of the linear polarizing layer <NUM> is a bidirectional absorption axis, and the absorption axis of the quarter-wave plate <NUM> is a unidirectional absorption axis. An inclination angle of the absorption axis of the protective layer <NUM> with respect to a first direction (for example, a Y direction shown in <FIG>) is defined as N degrees. The bidirectional absorption axis means that a laminated layer (for example, the protective layer <NUM> or the linear polarizing layer <NUM>) has the same effects on light in a positive direction and a negative direction of the absorption axis. The unidirectional absorption axis means that a laminated layer (for example, the quarter-wave plate <NUM>) has different effects on light in a direction positive and a negative direction of the absorption axis. For example, because the absorption axis of the protective layer <NUM> is the bidirectional absorption axis, the light intensity of light passing through the protective layer <NUM> is the same when the absorption axis of the protective layer <NUM> is inclined by <NUM> degrees and <NUM> degrees with respect to the first direction. Because the absorption axis of the quarter-wave plate <NUM> is the unidirectional absorption axis, the light intensity of light passing through the quarter-wave plate <NUM> is different when the absorption axis of the quarter-wave plate <NUM> is inclined by <NUM> degrees and <NUM> degrees with respect to the first direction. It may be understood that, the N degrees can be any angle. An angle between the absorption axis of the protective layer <NUM> and the first direction and an angle between the absorption axis of the linear polarizing layer <NUM> and the first direction (for example, the Y direction shown in <FIG>) are N degrees. An angle between the absorption axis of the quarter-wave plate <NUM> and a positive direction of the first direction is N-<NUM> degrees. In this implementation, N is <NUM> degrees, that is, the absorption axis of the quarter-wave plate <NUM> is consistent with the positive direction of the first direction. The angle between the absorption axis of the quarter-wave plate <NUM> and the absorption axis of the protective layer <NUM> is <NUM> degrees. In other words, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is zero degrees.

An example in which the electronic device <NUM> is a mobile phone is used below for description.

<FIG> is a schematic diagram of an application scenario when fingerprint recognition is performed by an electronic device according to an implementation of this application. <FIG> is a schematic diagram when fingerprint recognition is performed by a partial structure of an electronic device according to an implementation of this application. A finger <NUM> touches a display panel <NUM> to enable the electronic device <NUM> to perform fingerprint recognition. The finger <NUM> is located on one side of a protective layer <NUM> away from a linear polarizing layer <NUM>, to facilitate an optical fingerprint recognition module <NUM> to perform fingerprint recognition. It may be understood that, there may also be a specific gap between the finger <NUM> and the protective layer <NUM>, and a surface of the finger <NUM> can reflect light to the display panel <NUM>.

External light <NUM> is incident from the protective layer <NUM> and transmitted to a functional substrate <NUM> through a reinforcing layer <NUM>, an optical adhesive layer <NUM>, the linear polarizing layer <NUM>, and a quarter-wave plate <NUM>. Part of the external light <NUM> is reflected by reflection units <NUM> into first reflected light <NUM>, and part of the external light <NUM> enters the optical fingerprint recognition module <NUM> through a light-transmitting area <NUM>. In actual application, only part of the first reflected light <NUM> cannot pass through the linear polarizing layer <NUM> after passing through the quarter-wave plate <NUM>, namely, is eliminated, while part of the first reflected light <NUM> can still be emitted from the protective layer <NUM> to reach the surface of the finger <NUM>. The first reflected light <NUM> emitted from the protective layer <NUM> is reflected by the surface of the finger <NUM> into second reflected light <NUM>. The second reflected light <NUM> enters the functional substrate <NUM> through the protective layer <NUM>, the reinforcing layer <NUM>, the optical adhesive layer <NUM>, the linear polarizing layer <NUM>, and the quarter-wave plate <NUM>, and is incident to the optical fingerprint recognition module <NUM> through the light-transmitting area <NUM> of the functional substrate <NUM>.

The reflection units <NUM> emit light <NUM>. The light <NUM> is emitted to the surface of the finger <NUM> through the quarter-wave plate <NUM>, the linear polarizing layer <NUM>, the optical adhesive layer <NUM>, the reinforcing layer <NUM>, and the protective layer <NUM>. The light <NUM> is reflected by the surface of the finger <NUM> into third reflected light <NUM>. The third reflected light <NUM> then enters the optical fingerprint recognition module <NUM> through the protective layer <NUM>, the reinforcing layer <NUM>, the optical adhesive layer <NUM>, the linear polarizing layer <NUM>, the quarter-wave plate <NUM>, and the light-transmitting area <NUM> of the functional substrate <NUM>. The optical fingerprint recognition module <NUM> performs fingerprint recognition.

An angle between an absorption axis of the protective layer <NUM> and an absorption axis of the linear polarizing layer <NUM> is zero degrees, and a luminous flux of the reflected light (for example, the second reflected light <NUM> or the third reflected light <NUM>) reflected from the surface of the finger <NUM> after passing through the protective layer <NUM> is roughly the same as that after passing through the linear polarizing layer <NUM>. In other words, the light intensity of light passing through the protective layer <NUM> is consistent with that of light passing through the linear polarizing layer <NUM>, to stabilize the light intensity of light passing through the display panel <NUM>, and improve the stability of the light passing through the display panel <NUM>, thereby improving the recognition precision of the optical fingerprint recognition module <NUM>.

<FIG> a flowchart of a method for preparing a laminated structure, not within the scope of the claimed invention. The method for preparing a laminated structure includes the following steps:.

In an implementation, the arranging the protective layer on one side of the linear polarizing layer away from the quarter-wave plate includes: arranging a reinforcing layer on one side of the linear polarizing layer away from the quarter-wave plate, and arranging the protective layer on one side of the reinforcing layer away from the linear polarizing layer.

In another implementation, the arranging a reinforcing layer on one side of the linear polarizing layer away from the quarter-wave plate includes: fixing the reinforcing layer on the linear polarizing layer through an optical adhesive layer.

<FIG> is a schematic diagram of absorption axes of laminated layers of a display panel according to a second implementation of this application. The display panel provided in the second implementation is roughly the same as the display panel provided in the first implementation, except that an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of a first direction is N+<NUM> degrees, where N is <NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees, and an angle between an absorption axis of a protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

The protective layer <NUM> can polarize light incident therein to form linearly polarized light, an angle between an absorption axis of a linear polarizing layer <NUM> and the absorption axis of the protective layer <NUM> is zero degrees, and there is no difference between a direction of the absorption axis of the protective layer <NUM> and a direction of the absorption axis of the linear polarizing layer <NUM>. Therefore, a luminous flux of light passing through the protective layer <NUM> is roughly the same as that of light passing through the linear polarizing layer <NUM>. In other words, the light intensity of the light passing through the protective layer <NUM> is consistent with that of the light passing through the linear polarizing layer <NUM>, and the stability of light passing through the display panel is improved, to stabilize the light intensity of the light passing through the display panel, and improve the stability of light entering an optical fingerprint recognition module, thereby improving the recognition precision of the optical fingerprint recognition module.

<FIG> is a schematic diagram of absorption axes of laminated layers of a display panel according to a third implementation of this application. The display panel provided in the third implementation is roughly the same as the display panel provided in the first implementation, except that an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of a first direction is N+<NUM>×<NUM> degrees, where N is <NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees, and an angle between an absorption axis of a protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

<FIG> is a schematic diagram of absorption axes of laminated layers of a display panel according to the fourth implementation of this application. The display panel provided in the fourth implementation is roughly the same as the display panel provided in the first implementation, except that an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of a first direction is N+<NUM>×<NUM> degrees, where N is <NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees, and an angle between an absorption axis of a protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

<FIG> is a schematic diagram of an absorption axis of a laminated structure according to a fifth implementation of this application. A laminated structure of a display panel provided in the fifth implementation is roughly the same as that of the display panel provided in the first implementation, except that an inclination angle of an absorption axis of a protective layer <NUM> with respect to a first direction (for example, a Y direction shown in <FIG>) is <NUM> degrees, namely, N is <NUM> degrees, an inclination angle of an absorption axis of a linear polarizing layer <NUM> with respect to the first direction (for example, the Y direction shown in <FIG>) is <NUM> degrees, and an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of the first direction is N-<NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees, and an angle between the absorption axis of the protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

<FIG> is a schematic diagram of an absorption axis of a laminated structure according to a sixth implementation of this application. A laminated structure of a display panel provided in the sixth implementation is roughly the same as that of the display panel provided in the first implementation, except that an inclination angle of an absorption axis of a protective layer <NUM> with respect to a first direction (for example, a Y direction shown in <FIG>) is <NUM> degrees, namely, N is <NUM> degrees, an inclination angle of an absorption axis of a linear polarizing layer <NUM> with respect to the first direction (for example, the Y direction shown in <FIG>) is <NUM> degrees, and an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of the first direction is N+<NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees, and an angle between the absorption axis of the protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

<FIG> is a schematic diagram of an absorption axis of a laminated structure according to a seventh implementation of this application. A laminated structure of a display panel provided in the seventh implementation is roughly the same as that of the display panel provided in the first implementation, except that an inclination angle of an absorption axis of a protective layer <NUM> with respect to a first direction (for example, a Y direction shown in <FIG>) is <NUM> degrees, namely, N is <NUM> degrees, an inclination angle of an absorption axis of a linear polarizing layer <NUM> with respect to the first direction (for example, the Y direction shown in <FIG>) is <NUM> degrees, and an angle between an absorption axis of a quarter-wave plate <NUM> and a positive direction of the first direction is N+<NUM>×<NUM> degrees. In this case, the angle between the absorption axis of the quarter-wave plate <NUM> and the positive direction of the first direction is <NUM> degrees (also <NUM> degrees), and an angle between the absorption axis of the protective layer <NUM> and the absorption axis of the quarter-wave plate <NUM> is <NUM> degrees.

Claim 1:
A laminated structure (<NUM>), wherein the laminated structure (<NUM>) comprises a protective layer, a linear polarizing layer (<NUM>), and a quarter-wave plate (<NUM>) that are laminated in sequence, wherein the protective layer (<NUM>) is arranged on one side of the linear polarizing layer (<NUM>) away from the quarter-wave plate (<NUM>), and an angle between the absorption axis of the linear polarizing layer (<NUM>) and an absorption axis of the quarter-wave plate (<NUM>) is <NUM> degrees characterized in that the protective layer (<NUM>) is used to polarize light to form linearly polarized light, and an angle between an absorption axis of the protective layer (<NUM>) and an absorption axis of the linear polarizing layer (<NUM>) is zero degrees.