Patent Description:
The present disclosure relates to the field of display technology, and particularly relates to a display module and a display device.

Nowadays, a circular polarizer is generally provided on the light outgoing side of a display screen of an electronic device, such that light transmitted out of the circular polarizer is linearly polarized light. However, polarized sunglasses currently on the market are equivalent to a linear polarizer, with an absorption axis in a horizontal (i.e. <NUM>°) or vertical (i.e. <NUM>°) direction. When a polarization direction of the light transmitted out of the circular polarizer is parallel to the absorption axis of the polarized sunglasses, the light transmitted out of the circular polarizer is absorbed by the polarized sunglasses, so that the human eyes cannot see the light, and thus cannot see pictures on the display screen, thereby degrading the user experience greatly.

The United States Patent Application Publication No. <CIT> relates an optical assembly in a display device includes a linear polarizer; a first quarter wave plate (QWP) layer under the linear polarizer, the first QWP layer having a negative dispersion characteristic; and a cholesteric liquid crystal (CLC) layer under the linear polarizer.

The United States Patent Application Publication No. <CIT> relates a display may include an optical film to promote sunglass-friendly viewing of the display. Displays may include linear polarizers. For example, a liquid crystal display may have a linear polarizer above a liquid crystal layer, whereas an organic light-emitting diode display may have a linear polarizer that forms a portion of a circular polarizer to reduce reflections in the display. Displays that emit linearly polarized light may not be compatible with polarized sunglasses. To ensure an optimal user experience for users wearing sunglasses, displays may include sunglass-friendly optical films. A sunglass-friendly optical film may be a film formed from a birefringent material such as a polymer or liquid crystal. The snnglass-friendly optical film may have an optical axis that is at a <NUM> angle relative to the optical axis of the underlying linear polarizer. The sunglass-friendly optical film may be patterned to have reduced thickness regions.

The China Patent Application Publication No. <CIT> relates a display screen is provided, including a display layer and a first light shielding layer. The display layer has a display surface, the first light shielding layer is arranged on the display surface and has a fingerprint recognition area, the fingerprint recognition area includes at least one first through hole sensing signals emitted and received by a fingerprint unit located below the display screen can be transmitted through the first through hole. A display device is provided, including the display screen and an optical fingerprint unit. The optical fingerprint unit is disposed at a side of the display layer away from the first light shielding layer and located at a position corresponding to an optical fingerprint recognition area. The fingerprint unit includes a light emitter and a light inductor, and a light signal emitted by the light emitter is transmitted to a fingerprint and received by the light inductor after being reflected by the fingerprint. A mobile terminal is provided.

An embodiment of the claimed invention provides a display module, including:.

Optionally, in an embodiment of the present disclosure, the diameter of the first through hole ranges from <NUM> to <NUM>.

Optionally, in an embodiment of the present disclosure, the first phase retarder includes second through holes in one-to-one correspondence with the first through holes; and
an orthographic projection of each second through hole on the display panel and an orthographic projection of the corresponding first through hole on the display panel have a overlapping field.

Optionally, in an embodiment of the present disclosure, the orthographic projection of the second through hole on the display panel covers the orthographic projection of the corresponding first through hole on the display panel.

Optionally, in an embodiment of the present disclosure, the second through hole is a circle concentric with the corresponding first through hole.

Optionally, in an embodiment of the present disclosure, the diameter d2 of the second through hole satisfies the formula: d2=d0+<NUM>'tanθ; where d0 represents the diameter of the first through hole, and θ represents a maximum imaging viewing angle;.

Optionally, in the embodiment of the present disclosure, the first phase retarder and the second phase retarder are both <NUM>/4λ wave plates.

Optionally, in an embodiment of the present disclosure, an included angle between a transmission axis direction of the linear polarizer and an optical axis of the second phase retarder is ±<NUM>°; and
an included angle between the transmission axis direction of the linear polarizer and an optical axis of the first phase retarder is ±<NUM>°.

Optionally, in an embodiment of the present disclosure, the display panel further includes a plurality of pixel units and wires arranged in gaps between every two adjacent ones of the pixel units; and
orthographic projections of the pixel units and the wires on the display panel do not overlap with orthographic projections of the transparent areas on the display panel.

Optionally, in an embodiment of the present disclosure, the light sensing detector includes a charge coupled photosensitive image sensor or a complementary metal-oxide-semiconductor photosensitive image sensor.

Optionally, in an embodiment of the present disclosure, the light sensing detector is disposed on a surface of the display panel away from light and arranged corresponding to the first through hole.

Optionally, in an embodiment of the present disclosure, one light sensing detector is provided, and the one light sensing detector corresponds to all of the first through holes, and an orthographic projection of the one light sensing detector on the display panel covers the orthographic projections of all the first through holes on the display panel; or
a plurality of light sensing detectors are provided, and the plurality of light sensing detectors are in one-to-one correspondence with the first through holes, and an orthographic projection of each of the plurality of light sensing detectors on the display panel covers the orthographic projection of the corresponding first through hole on the display panel.

Correspondingly, an embodiment of the present disclosure further provides a display device, including the aforementioned display module.

To make the object, technical solutions and advantages of the present disclosure more apparent, specific implementations of the display module and the display device provided in embodiments of the present disclosure are described in detail below in conjunction with the accompanying drawings. It should be understood that the embodiments described below are only used for illustrating and explaining the present disclosure, instead of limiting the present disclosure. Moreover, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. It needs to be noted that the thicknesses and shapes of the layers of film in the drawings do not reflect the true scale of the display module, and are merely intended to illustrate the present disclosure. Furthermore, same or similar reference numerals throughout represent same or similar elements or elements having same or similar functions.

Embodiments of the present disclosure provide a display module, as shown in <FIG>, including:.

For the display module provided in the embodiments of the present disclosure, the second phase retarder is arranged on the side of the linear polarizer facing away from the display panel, and since the light output from the display panel becomes linearly polarized light after passing through the first phase retarder and the linear polarizer, and the linearly polarized light is converted into circularly polarized light after passing through the second phase retarder. As the circularly polarized light can pass through the linear polarizer, when a person wears polarized sunglasses, regardless of whether an absorption axis of the polarized sunglasses is in a horizontal or vertical direction, there is always light incident to the human eyes through the polarized sunglasses, so that the observer can see a picture displayed on the display panel.

An organic light emitting diodes (OLEDs), or called organic electroluminescent diodes, have the advantages of low energy consumption, a low production cost, self-illumination, a wide viewing angle and fast response, etc. In a specific implementation, in the embodiments of the present disclosure, the display panel may be an OLED display panel. Specifically, the display panel may include a plurality of pixel units and wires arranged in gaps between every two adjacent ones of the pixel units. The pixel units have organic light emitting diodes (OLED) and pixel circuits for driving the OLEDs to emit light. The wires are used for inputting various drive signals to the pixel circuits. Further, the display panel may be a rigid display panel, for example, an underlying substrate of the display panel may be a glass substrate, a sapphire substrate, a quartz substrate, a plastic substrate, or the like. The display panel may also be a flexible display panel, for example, the underlying substrate of the display panel may be a Polyimide (PI) substrate, and is not limited herein.

In practical applications, the first phase retarder and the linear polarizer are generally used to solve the problem that the display panel reflects ambient light. Specifically, the ambient light is generally natural light, and when the ambient light passes through the linear polarizer, only the light whose vibration direction is parallel to a transmission axis of the linear polarizer can pass through the linear polarizer, and after passing through the second phase retarder, the natural light is still natural light without change of its polarization state. Therefore, the ambient light is still natural light after passing through the second phase retarder. After the ambient light passes through the linear polarizer, only half of the light can pass. Taking the output light being horizontally polarized light as an example, after the horizontally polarized light passes through the first phase retarder, the light can be converted into right-handed circularly polarized light (taking right-handed light as an example), and the right-handed circularly polarized light can be converted into left-handed circularly polarized light after being reflected by the display panel, and the left-handed circularly polarized light becomes linearly polarized light after passing through the first phase retarder, but the vibration direction of the linearly polarized light after passing through the first phase retarder is perpendicular to the transmission axis direction of the linear polarizer, so that the light reflected by the display panel cannot pass the linear polarizer, thereby solving the problem that the display panel reflects the ambient light, and improving the display effect.

Specifically, in the embodiments of the present disclosure, the aforementioned first phase retarder and second phase retarder may be <NUM>/<NUM>λ wave plates, and may be other phase retarders, and are not limited herein. In a specific implementation, to obtain circularly polarized light, in the embodiment of the present disclosure, the transmission axis direction of the linear polarizer may be set to an angle of ±<NUM>° with respect to an optical axis of the second phase retarder, so that the polarized light passing through the linearly polarizer is converted into circularly polarized light after passing through the second phase retarder. Similarly, the transmission axis direction of the linear polarizer may also be set to an angle of ±<NUM>° with respect to an optical axis of the first phase retarder. Specifically, generally the light emitted by the display panel is approximately natural light, and after passing through the first phase retarder <NUM>, the light is still natural light, and then after passing through the linear polarizer <NUM>, the light is converted into linearly polarized light. As the included angle between the vibration direction of the converted linearly polarized light and the optical axis of the second phase retarder <NUM> can be ±<NUM>°, the light converted into the linearly polarized light can be converted into circularly polarized light after passing through the second phase retarder <NUM>. As the circularly polarized light can be transmitted through the linearly polarizer, the output light from the display module can enter the human eyes through the polarized sunglasses.

A fingerprint is an invariant feature of the human body that is inherently unique and distinguishable from others. It consists of a series of ridges and valleys on the skin surface of a fingertip. The compositional details of these ridges and valleys determine the uniqueness of the fingerprint pattern. A display panel with a fingerprint recognition function developed therefrom has been used for personal identity verification, which increases information security of a display module. Therefore, the display module can be integrated with the fingerprint recognition function. The implementations integrated with the fingerprint recognition function of the present disclosure are described in detail below with reference to specific embodiments. It needs to be noted that the embodiments are only for better explanation of the present disclosure, but do not limit the present disclosure.

Generally, to protect devices, in a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the display module may further include a protective cover <NUM> arranged on a side of the second phase retarder <NUM> facing away from the display panel <NUM>.

Further, in the claimed invention, at least one of the second phase retarder and the linear polarizer includes a plurality of first through holes for implementing pinhole imaging;.

<FIG> is a structural schematic diagram in which the first through hole is only provided in the second phase retarder. Specifically, in an embodiment of the present disclosure, as shown in <FIG>, the second phase retarder <NUM> may include a plurality of first through holes <NUM> for implementing pinhole imaging;.

Further, to improve the pinhole imaging accuracy, the orthographic projection of the transparent area <NUM> on the display panel <NUM> may cover the orthographic projection of the corresponding first through hole <NUM> on the display panel <NUM>.

In practical applications, the pattern of the first through hole may be any pattern capable of implementing the principle of pinhole imaging. Further, the pattern of each first through hole <NUM> is set to a circular shape, the transparent area <NUM> is also set to a circular shape, and the transparent area <NUM> is arranged concentrically with the corresponding first through hole <NUM>. It needs to be noted that the diameter of the first through hole <NUM> needs to meet the requirement on the pinhole diameter in the pinhole imaging principle. For example, the diameter of the first through hole <NUM> may be set to <NUM>-<NUM>; for example, the diameter of the first through hole <NUM> may be set to <NUM>, or <NUM> or <NUM>. In practical applications, the specific value of the diameter of the first through hole <NUM> needs to be determined through designing according to the actual application environment, and is not limited herein.

Specifically, during fingerprint recognition, light emitted by the pixel units irradiates the fingerprint of a finger, and the fingerprint reflects the incident light, and an image is formed on the light sensing detector <NUM> through the first through hole <NUM> by using the pinhole imaging principle. Then the image formed on the light sensing detector <NUM> is acquired, and a fingerprint image is determined according to the acquired image; and fingerprint recognition is carried out according to the determined fingerprint image to achieve the fingerprint recognition function.

Specifically, <FIG> is a schematic diagram illustrating the polarization states of light corresponding to the structure shown in <FIG>. As shown in <FIG>, the light emitted by the pixel units in the display panel <NUM> is approximately natural light, and after passing through the first phase retarder <NUM>, the light is still natural light, and then after passing through the linear polarizer <NUM>, the light is converted into linearly polarized light. Using the output light being horizontally polarized light as an example, after the horizontally polarized light passes through the second phase retarder <NUM>, the light can be converted into right-handed circularly polarized light (using right-handed circularly polarized light as an example in the figure); the right-handed circularly polarized light can be converted into left-handed circularly polarized light after being reflected by the finger; the left-handed circularly polarized light is still left-handed circularly polarized light after passing through the first through hole <NUM> of the second phase retarder <NUM>; then the left-handed circularly polarized light is converted into linearly polarized light after passing through the linear polarizer <NUM>; and the linearly polarized light becomes circularly polarized light (using right-handed polarized light as an example) after passing through the first phase retarder <NUM>. The left-handed circularly polarized light reflected by the finger that has not passed through the first through hole <NUM> becomes linearly polarized light after passing through the second phase retarder <NUM>, but the vibration direction of the linearly polarized light after passing through the second phase retarder <NUM> is perpendicular to the transmission axis direction of the linear polarizer <NUM>, so that the light reflected by the finger cannot enter the light sensing detector <NUM> through a path other than the first through hole <NUM>, and thus the accuracy of pinhole imaging can be improved.

In a specific implementation, in embodiments of the present disclosure, the first through hole <NUM> is a via hole running through the second phase retarder <NUM>, and the plurality of first through holes <NUM> included in the second phase retarder <NUM> may be uniformly distributed. Specifically, the first through holes <NUM> may be uniformly distributed in the entire second phase retarder <NUM>; or may be uniformly distributed only in a specific area of the second phase retarder <NUM>, which is not specifically limited herein. Further, the first through holes <NUM> may be arranged in an array in the second phase retarder <NUM>. In addition, a distance between centers of two adjacent first through holes may be determined through designing according to the actual application environment, and is not limited herein.

Generally, during the pinhole imaging, an image formed through the pinhole center is relatively clear, and the closer to edges, the more blurred an image is, so images formed in the light sensing detector by the fingerprint through the plurality of first through holes can be acquired. However, in the acquired images of the fingerprint formed through the plurality of first through holes, generally there are same areas of the fingerprint, that is, common imaging portions. Thus, in determining the fingerprint image, the acquired images formed through the plurality of first through holes are extracted and processed, and the extracted and processed fingerprint images are stitched, to integrate the images into a complete and clear fingerprint image for fingerprint recognition, thus improving the accuracy.

Generally, the transparent areas need to be provided at positions that are not blocked by the pixel units and the wires, otherwise the effect of the pinhole imaging can be affected, or even imaging on the light sensing detector <NUM> cannot be achieved. In a specific implementation, in embodiments of the present disclosure, the transparent areas may be hollowed areas in the display panel. In an actual preparation process, holes are formed in portions of the substrate corresponding to the transparent areas by cutting or etching to produce hollowed areas. Alternatively, orthographic projections of the transparent areas on the display panel do not overlap with orthographic projections of the pixel units and the wires on the display panel, thus, the substrate may be not cut, but the pixel units, the film layers, and the wires on the underlying substrate are avoided to form the transparent areas.

To further reduce the influence on the pinhole imaging effect, in the claimed invention, as shown in <FIG>, the diameter d1 of the transparent area <NUM> satisfies the formula: d1=d0+2htanθ, where d0 represents the diameter of the first through hole <NUM>, θ represents a maximum imaging viewing angle (i.e. an included angle between light closest to the edge in the light beam after passing through the first through hole in pinhole imaging and a normal line), and h represents a distance between a lower surface S1 of the second phase retarder <NUM> facing to the display panel <NUM> and a lower surface S2 of the display panel <NUM> on a side facing away from the second phase retarder <NUM>. This allows all of the light passing through the first through holes <NUM> to be incident on the light sensing detector <NUM> through the corresponding transparent areas <NUM>.

In a specific implementation, in the aforementioned display module provided in the embodiments of the present disclosure, to improve the resolution precision of fingerprint recognition by each fingerprint recognition unit, the linear polarizer <NUM>, the first phase retarder <NUM>, and the display panel <NUM> may be made as thin as possible. For example, the thickness of a circular polarizer composed of the first phase retarder <NUM> and the linear polarizer <NUM> may range from <NUM> to <NUM>. In practical applications, the thicknesses of the linear polarizer <NUM>, the first phase retarder <NUM>, and the display panel <NUM> may be determined through designing according to the actual application environment, and is not limited herein.

In a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the light sensing detector <NUM> is disposed on a surface of the display panel <NUM> away from light and arranged corresponding to the first through hole <NUM>. Specifically, the light sensing detector <NUM> and the first through hole <NUM> are respectively located on two sides of the display panel <NUM>, and the light sensing detector <NUM> is located at a position corresponding to the first through hole <NUM> to facilitate imaging on the light sensing detector <NUM>.

In a specific implementation, one light sensing detector may be arranged in the display module, where the light sensing detector corresponds to all of the first through holes, and the orthographic projection of the light sensing detector on the display panel covers the orthographic projections of all the first through holes on the display panel; images are formed in areas of the light sensing detector through the first through holes, and then the images in the areas of the light sensing detector are processed to achieve the function of recognizing the fingerprint. Alternatively, a plurality of light sensing detectors may also be arranged in the display module, where the light sensing detectors are in one-to-one correspondence with the first through holes, and the orthographic projection of each light sensing detector on the display panel covers the orthographic projection of the corresponding first through hole on the display panel. That is, each light sensing detector is arranged corresponding to one first through hole; in addition, one light-sensing detector may also correspond to a plurality of first through holes. In practical applications, this needs to be determined through designing according to the specific application environment, and is not limited herein.

In a specific implementation, in embodiments of the present disclosure, the light sensing detector may include a charge-coupled device (CCD) photosensitive image sensor or a complementary metal-oxide-semiconductor (CMOS) photosensitive image sensor. Of course, the light sensing detector may also be any other photosensitive image sensor capable of implementing recognition of the fingerprint, which is not specifically limited herein.

<FIG> is a structural schematic diagram in which the first through hole is only provided in the linear polarizer. The display module shown in <FIG> and the display module shown in <FIG> are similarly implemented except for the specific position of the first through hole. Only differences between the structures shown in <FIG> and <FIG> will be described below, and their similarities are not described herein.

In a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the linear polarizer <NUM> may include a plurality of first through holes <NUM> for implementing pinhole imaging;.

<FIG> is a schematic diagram of a polarization state of light corresponding to the structure shown in <FIG>. Differently from <FIG>, the left-handed circularly polarized light reflected by the finger becomes linearly polarized light after passing through the second phase retarder <NUM>, and then after the linearly polarized light passes through the first through hole <NUM> on the linear polarizer <NUM>, it is still linearly polarized light, and the linearly polarized light becomes circularly polarized light (using right-handed polarized light as an example in the figure) after passing through the first phase retarder <NUM>. As to the linearly polarized light that has not passed through the first through hole <NUM> obtained after the light reflected by the finger passes through the second phase retarder <NUM>, it cannot pass through linear polarizer <NUM> because its vibration direction is perpendicular to the transmission axis direction of the linear polarizer <NUM>, so that the light reflected by the finger cannot enter the light sensing detector <NUM> through a path other than the first through hole <NUM>, and thus the accuracy of pinhole imaging can be improved.

In a specific implementation, in embodiments of the present disclosure, the first through hole <NUM> is a via hole running through the linear polarizer <NUM>. Moreover, the plurality of first through holes <NUM> included in the linear polarizer <NUM> may be uniformly distributed. Specifically, the first through holes <NUM> may be uniformly distributed in the entire linear polarizer <NUM>; or may be uniformly distributed only in a specific area of the linear polarizer <NUM>, which is not specifically limited herein. Further, the first through holes <NUM> may be arranged in an array in the linear polarizer <NUM>. Moreover, a distance between centers of two adjacent first through holes may be determined according to the actual application environment, and is not limited herein.

To further reduce the influence on the pinhole imaging effect, in the claimed invention, as shown in <FIG>, the diameter d1 of the transparent area <NUM> satisfies the formula: d1=d0+2htanθ, where d0 represents the diameter of the first through hole <NUM>, and θ represents a maximum imaging viewing angle; (i.e. an included angle between light closest to the edge in the light beam after passing through the first through hole <NUM> in pinhole imaging and a normal line), and h represents a distance between a lower surface S3 of the linear polarizer <NUM> facing to the display panel <NUM> and a lower surface S2 of the display panel <NUM> on a side facing away from the second phase retarder <NUM>. This allows all of the light passing through the first through holes <NUM> to be incident on the light sensing detector <NUM> through the corresponding transparent areas <NUM>.

<FIG> is a structural schematic diagram in which the first through hole is provided in both the second phase retarder and the linear polarizer. The display module shown in <FIG> and the display module shown in <FIG> are similarly implemented except for the specific position of the first through hole. Only differences between the structures shown in <FIG> and <FIG> will be described below, and their similarities are not described herein.

In a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the second phase retarder <NUM> and the linear polarizer <NUM> may include a plurality of first through holes <NUM> for implementing pinhole imaging;.

<FIG> is a schematic diagram illustrating polarization states of light corresponding to the structure shown in <FIG>. Differently from <FIG>, after the left-handed circularly polarized light reflected by the finger passes through the first through holes <NUM> in the second phase retarder <NUM> and the linear polarizer <NUM>, it is still left-handed circularly polarized light, and the left-handed circularly polarized light becomes linearly polarized light after passing through the first phase retarder <NUM>. As to the linearly polarized light obtained after the light reflected by the finger that has not passed through the first through holes <NUM> passes through the second phase retarder <NUM>, it cannot pass through the linear polarizer <NUM> because its vibration direction is perpendicular to the transmission axis direction of the linear polarizer <NUM>, so that the light reflected by the finger cannot enter the light sensing detector <NUM> through a path other than the first through holes <NUM>, and thus the accuracy of pinhole imaging can be improved.

In a specific implementation, in embodiments of the present disclosure, the first through holes <NUM> are via holes running through the second phase retarder <NUM> and the linear polarizer <NUM>. Moreover, the plurality of first through holes <NUM> included in the second phase retarder <NUM> and the linear polarizer <NUM> may be uniformly distributed. The first through holes <NUM> may be uniformly distributed in the entire second phase retarder <NUM> and linear polarizer <NUM>; or may be uniformly distributed only in a specific area of the second phase retarder <NUM> and linear polarizer <NUM>, which is not specifically limited herein. Further, the first through holes <NUM> may be arranged in an array in the second phase retarder <NUM> and the linear polarizer <NUM>. Moreover, a distance between centers of two adjacent first through holes may be determined according to the actual application environment, and is not limited herein.

To further reduce the influence on the pinhole imaging effect, in a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the diameter d1 of the transparent area <NUM> may satisfy the formula: d1=d0+2htanθ, where d0 represents the diameter of the first through hole <NUM>, and θ represents a maximum imaging viewing angle; (i.e. an included angle between light closest to the edge in the light beam after passing through the first through hole <NUM> in pinhole imaging and a normal line), and h represents a distance between a lower surface S3 of the linear polarizer <NUM> facing to the display panel <NUM> and a lower surface S2 of the display panel <NUM> on a side facing away from the second phase retarder <NUM>. This allows all of the light passing through the first through holes <NUM> to be incident on the light sensing detector <NUM> through the corresponding transparent areas <NUM>.

Further, in a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the first phase retarder <NUM> may include second through holes <NUM> in one-to-one correspondence with the first through holes <NUM>;
where an orthographic projection of each second through hole <NUM> on the display panel <NUM> and an orthographic projection of the corresponding first through hole <NUM> on the display panel <NUM> have a overlapping field.

The structure of the display module shown in <FIG> differs from the structure of the display module shown in <FIG> in that in the structure shown in <FIG>, the first phase retarder <NUM> includes second through holes <NUM>, and other portions in <FIG> are structurally same as those in <FIG>, and will not be repeated here. The light polarization states corresponding to the structure shown in <FIG> is similar to that in <FIG>, and differs in that the linearly polarized light obtained after the light reflected by the finger passes through the linear polarizer <NUM> is still linearly polarized light after passing through the second through holes <NUM>.

Further, to improve the pinhole imaging accuracy, the orthographic projection of each second through hole <NUM> on the display panel <NUM> may cover the orthographic projection of the corresponding first through hole <NUM> on the display panel <NUM>.

In a specific implementation, in embodiments of the present disclosure, the second through hole is a circle concentric with the corresponding first through hole.

To further reduce the influence on the pinhole imaging effect, in a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the diameter d2 of the second through hole <NUM> may satisfy the formula: d2=d0+<NUM>'tanθ, where d0 represents the diameter of the first through hole <NUM>, θ represents a maximum imaging viewing angle, and h' represents a distance between a lower surface S1 of the second phase retarder <NUM> facing to the display panel <NUM> and a lower surface S4 of the first phase retarder <NUM> facing to the display panel <NUM>. This allows all of the light passing through the first through holes <NUM> to be incident on the light sensing detector <NUM> through the corresponding second through holes <NUM>.

<FIG> is a structural schematic diagram of another display module provided in embodiments of the present disclosure. As shown in <FIG>, the structure shown in <FIG> differs from that shown in <FIG> in that the first phase retarder in <FIG> includes second through holes. Only differences between the structures shown in <FIG> and <FIG> will be described below, and their similarities are not described herein.

In a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the first phase retarder <NUM> may include second through holes <NUM> in one-to-one correspondence with the first through holes <NUM>; where an orthographic projection of each second through hole <NUM> on the display panel <NUM> and an orthographic projection of the corresponding first through hole <NUM> on the display panel <NUM> have a overlapping field. Further, to improve the pinhole imaging accuracy, the orthographic projection of each second through hole <NUM> on the display panel <NUM> may cover the orthographic projection of the corresponding first through hole <NUM> on the display panel <NUM>.

The light polarization states corresponding to the structure shown in <FIG> is similar to that in <FIG>, and differs in that the linearly polarized light obtained after the light reflected by the finger passes through the linear polarizer <NUM> is still linearly polarized light after passing through the second through holes <NUM>.

In a specific implementation, in embodiments of the present disclosure, the second through hole is a circle concentric with the corresponding first through hole. To further reduce the influence on the pinhole imaging effect, in a specific implementation, in embodiments of the present disclosure, as shown in <FIG>, the diameter d2 of the second through hole <NUM> may satisfy the formula: d2=d0+<NUM>'tanθ, where d0 represents the diameter of the first through hole <NUM>, θ represents a maximum imaging viewing angle, and h' represents a distance between a lower surface S4 of the first phase retarder <NUM> facing to the display panel <NUM> and an upper surface S5 of the first phase retarder <NUM> facing away from the display panel <NUM>; that is, h' represents the thickness of the first phase retarder <NUM>. This allows all of the light passing through the first through holes <NUM> to be incident on the light sensing detector <NUM> through the corresponding second through holes <NUM>.

<FIG> is a structural schematic diagram of another display module provided in an embodiment of the present disclosure. As shown in <FIG>, the structure shown in <FIG> differs from that shown in <FIG> in that the first phase retarder in <FIG> includes second through holes. Only differences between the structures shown in <FIG> and <FIG> will be described below, and their similarities are not described herein.

The light polarization states corresponding to the structure shown in <FIG> differs from that in <FIG> in that the circularly polarized light obtained after the light reflected by the finger passes through the linear polarizer <NUM> is still circularly polarized light after passing through the second through holes <NUM>.

Based on the same disclosed concept, an embodiment of the present disclosure further provides a display device, including any of the aforementioned display modules provided in the embodiments of the present disclosure. The problem solving principle of the display device is similar to that of the foregoing display module. For the implementations of the display device, reference may be made to the embodiments of the foregoing display module, and the repeated description is omitted.

In specific implementations, the display device provided in the embodiment of the present disclosure may be a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, or any other product or component with a display function. Other indispensable components of the display device are present as understood by those skilled in the art, and are not described herein, nor should they be construed as limiting the present disclosure.

For the display module and display device provided in embodiments of the present disclosure, the second phase retarder is arranged on the side of the linear polarizer facing away from the display panel, and as output light from the display panel becomes linearly polarized light after passing through the first phase retarder and the linear polarizer, and the linearly polarized light is converted into circularly polarized light after passing through the second phase retarder, thus, when a person wears polarized sunglasses, regardless of whether the absorption axis of the polarized sunglasses is in a horizontal or vertical direction, there is always light incident to the human eyes through the polarized sunglasses, so that the observer can see a picture displayed on the display panel.

Claim 1:
A display module, comprising:
a display panel (<NUM>) which is an organic electroluminescent display panel;
a first phase retarder (<NUM>) located on a side of an out-light surface of the display panel (<NUM>);
a linear polarizer (<NUM>) located on a side of the first phase retarder (<NUM>) facing away from the display panel; and
a second phase retarder (<NUM>) covering a side of the linear polarizer (<NUM>) facing away from the display panel (<NUM>);
wherein at least one of the second phase retarder and the linear polarizer comprises a plurality of first through holes (<NUM>) for implementing pinhole imaging;
a display area of the display panel comprises transparent areas in one-to-one correspondence with the plurality of first through holes (<NUM>); an orthographic projection of each transparent area on the display panel (<NUM>) and an orthographic projection of a corresponding first through hole (<NUM>) on the display panel have an overlapping field; and
the display module further comprises a light sensing detector (<NUM>) for receiving an image of a fingerprint formed through the first through hole (<NUM>);
wherein the orthographic projection of the transparent area on the display panel covers the orthographic projection of the corresponding first through hole on the display panel;
wherein each of the plurality of first through holes (<NUM>) is a circle; and the transparent area is a circle concentric with a corresponding first through hole; characterized in that,
wherein a diameter d<NUM> of the transparent area satisfies a formula: d<NUM>=d<NUM>+2htanθ; wherein d<NUM> represents a diameter of the first through hole, and θ represents a maximum imaging viewing angle;
in a case the second phase retarder (<NUM>) comprises the first through holes, h represents a distance between a lower surface of the second phase retarder facing to the display panel and a lower surface of the display panel facing away from the second phase retarder; and
in a case the linear polarizer (<NUM>) includes the first through holes, or the second phase retarder and the linear polarizer include the first through holes, h represents a distance between a lower surface of the linear polarizer facing to the display panel and a lower surface of the display panel facing away from the second phase retarder.