Display module and electronic equipment

Abstract

The embodiment of the invention discloses a display module and electronic equipment, the display module comprises a display screen, a first polarization piece, a semi-transparent and semi-reflective mirror, a second lens and a light guide assembly which are arranged in sequence, the light guide assembly is arranged on the fourth surface of the second lens, and the fourth surface of the second lens is the surface far away from the first polarization piece. Light emitted by the display screen is modulated into first circularly polarized light through the first polarization piece, the first circularly polarized light enters the light guide assembly through the semi-transparent and semi-reflecting mirror and the second lens and is modulated and reflected through the light guide assembly to form second circularly polarized light, and the second circularly polarized light enters the semi-transparent and semi-reflecting mirror through the second lens and is reflected into third circularly polarized light through the semi-transparent and semi-reflecting mirror. The third circularly polarized light passes through the second lens and is emitted through the light guide assembly. The display module is few in optical elements and simple in structure, the film pasting yield is improved under the condition of achieving small size and light weight, it is guaranteed that MTF approaches the diffraction limit, and therefore the optical performance is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a display module and an electronic device. Background Art

[0002] Currently, with the development of electronic technologies, electronic devices are more and more widely used. For example, Augmented Reality (AR) devices, Virtual Reality (VR) devices, etc. have been widely used in daily life. Among them, AR devices, VR devices, etc. are usually provided with a display module, and the display module includes a display screen and a light guide component. The light guide component can guide the light emitted by the display screen to the eyes of the user, so that the user can see the image displayed on the display screen. To facilitate portability and use, electronic devices need to develop towards miniaturization, light weight, and high performance, and thus require the corresponding optical system to achieve high imaging quality with a relatively compact structure. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a display module and an electronic device, which can improve the film pasting yield and ensure the optical performance while achieving miniaturization and light weight.

[0004] In a first aspect, an embodiment of the present invention provides a display module, which includes a display screen, a first polarizer, a semi-transmissive semi-reflective mirror, a second lens, and a light guide component arranged in sequence. The light guide component is arranged on a fourth surface of the second lens, and the fourth surface of the second lens is a surface away from the first polarizer.

[0005] The light emitted by the display screen is modulated into a first circularly polarized light by the first polarizer. The first circularly polarized light passes through the semi-transmissive semi-reflective mirror and the second lens and enters the light guide component, is modulated and reflected by the light guide component to form a second circularly polarized light. The second circularly polarized light passes through the second lens and enters the semi-transmissive semi-reflective mirror, is reflected by the semi-transmissive semi-reflective mirror into a third circularly polarized light. The third circularly polarized light passes through the second lens and is emitted through the light guide component.

[0006] Optionally, the fourth surface of the second lens is a concave surface, and the absolute value of the radius of curvature of the fourth surface is greater than 25 mm.

[0007] Optionally, the third surface of the second lens is a convex surface, and the third surface is a surface close to the first polarizer.

[0008] Optionally, the semi-transmissive semi-reflective mirror includes a first lens and a semi-transmissive semi-reflective film. The semi-transmissive semi-reflective film is arranged on a first surface or a second surface of the first lens. The first surface of the first lens is a surface close to the first polarizer, and the second surface of the first lens is a surface away from the first polarizer.

[0009] Optionally, the first surface of the first lens is convex, and the second surface of the first lens is concave.

[0010] Optionally, the thickness range of the first lens is 0.2 mm to 3 mm, the thickness range of the second lens is 0.3 mm to 2.5 mm, the refractive index range of the first lens and the second lens is 1.5 to 2.0, and the dispersion range of the first lens and the second lens is 20 to 70.

[0011] Optionally, the first polarizing member is disposed on the surface of the display screen, and the distance between the transflective film and the display screen is ≥ 0.1 mm.

[0012] Optionally, the light guide assembly includes a quarter-wave plate and a second polarizing member, and the quarter-wave plate is located between the second polarizing member and the fourth surface;

[0013] The light emitted by the display screen is modulated by the first polarizing member into a first circularly polarized light. The first circularly polarized light passes through the transflective mirror and the second lens and enters the quarter-wave plate. After being modulated by the quarter-wave plate into a first linearly polarized light, it is reflected by the second polarizing member to the quarter-wave plate, and then modulated by the quarter-wave plate into a second circularly polarized light and reflected by the transflective mirror into a third circularly polarized light, and enters the quarter-wave plate. After being modulated by the quarter-wave plate into a second linearly polarized light, it is emitted through the second polarizing member.

[0014] Optionally, the polarization direction of the first linearly polarized light is different from the polarization direction of the second linearly polarized light, the polarization direction of the first circularly polarized light is different from the polarization direction of the third circularly polarized light. The first linearly polarized light is a vertical linearly polarized light perpendicular to the optical axis direction of the second polarizing member, and the second linearly polarized light is a horizontal linearly polarized light parallel to the optical axis direction of the second polarizing member.

[0015] In a second aspect, an embodiment of the present invention further provides an electronic device, which includes:

[0016] A device housing and a circuit board, and the circuit board is disposed inside the device housing;

[0017] The display module as described in the first aspect is disposed on the device housing and is connected to the circuit board.

[0018] The display module provided by an embodiment of the present invention includes a display screen, a first polarizer, a semi-transmissive and semi-reflective mirror, a second lens, and a light guide assembly arranged in sequence. The light guide assembly is disposed on a fourth surface of the second lens. The light emitted by the display screen is modulated into a first circularly polarized light by the first polarizer. The first circularly polarized light passes through the semi-transmissive and semi-reflective mirror and the second lens and enters the light guide assembly, and is modulated and reflected by the light guide assembly to form a second circularly polarized light. The second circularly polarized light passes through the second lens and enters the semi-transmissive and semi-reflective mirror, and is reflected by the semi-transmissive and semi-reflective mirror into a third circularly polarized light. The third circularly polarized light passes through the second lens and is emitted through the light guide assembly. This display module has few optical elements and a simple structure. Under the condition of realizing miniaturization and light weight, the film sticking yield is improved, and the MTF is guaranteed to be close to the diffraction limit, thereby ensuring the optical performance of the display module. Description of the Drawings

[0019] Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0020] Figure 1 is a schematic structural diagram of the display module according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of the optical path propagation path of the display module according to an embodiment of the present invention;

[0022] Figure 3 is a two-dimensional structural diagram of the optical path simulation of the display module according to an embodiment of the present invention;

[0023] Figure 4 is a simulated MTF curve graph of the display module according to an embodiment of the present invention;

[0024] Figure 5 is a simulated spot diagram of the display module according to an embodiment of the present invention;

[0025] Figure 6 is a simulated distortion curve graph of the display module according to an embodiment of the present invention;

[0026] Figure 7 is a schematic structural diagram of the electronic device according to an embodiment of the present invention.

[0027] Reference Signs:

[0028] 100 - Display module; 1 - Display screen; 2 - First polarizer; 3 - Semi-transmissive and semi-reflective film; 4 - First lens; 41 - First surface; 42 - Second surface; 5 - Second lens; 51 - Third surface; 52 - Fourth surface; 6 - Light guide assembly; 61 - Quarter-wave plate; 62 - Second polarizer; 7 - Semi-transmissive and semi-reflective mirror; 101 - First circularly polarized light; 102 - Second circularly polarized light; 103 - Third circularly polarized light; 104 - Frame; 105 - Lens. Detailed Embodiments

[0029] The present application will be described based on embodiments, but the present application is not limited to these embodiments. In the following detailed description of the present application, some specific details are described in detail. Those skilled in the art can fully understand the present application without the description of these details. In order to avoid obscuring the essence of the present application, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0030] In addition, those of ordinary skill in the art should understand that the accompanying drawings provided herein are for illustrative purposes only, and the drawings are not necessarily drawn to scale.

[0031] Unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0032] Unless the context clearly requires otherwise, words such as "including" and "comprising" in the entire application document should be interpreted as having an inclusive meaning rather than an exclusive or exhaustive meaning; that is, it is the meaning of "including but not limited to".

[0033] In the description of the present application, it should be understood that terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0034] This embodiment provides a display module 100, as Figure 1 shown, the display module 100 includes a display screen 1, a first polarizing element 2, a semi-transmissive and semi-reflective mirror 7, a second lens 5, and a light guide assembly 6 arranged in sequence. As Figure 2As shown, the light rays emitted by the display screen 1 in different directions are polarized into first circularly polarized light 101 by the first polarizing element 2. The first circularly polarized light 101 passes through the semi-transmissive semi-reflective mirror 7 and the second lens 5 and enters the light guide assembly 6. After being modulated and reflected by the light guide assembly 6, it forms second circularly polarized light 102. The second circularly polarized light 102 passes through the second lens 5 and enters the semi-transmissive semi-reflective mirror 7. After being reflected by the semi-transmissive semi-reflective mirror 7, it becomes third circularly polarized light 103. The third circularly polarized light 103 passes through the second lens 5 and is emitted through the light guide assembly 6. The above display module 100 enables the light rays to be reflected multiple times between the semi-transmissive semi-reflective mirror 7 and the light guide assembly 6, thereby enabling the implementation of a folded optical path solution, meeting the requirements of lightweight of the display module 100, while having high image quality, a suitable viewing angle, and being able to improve the comfort and experience of users when using it.

[0035] In some embodiments, the above second lens 5, semi-transmissive semi-reflective mirror 7, and display screen 1 can be a coaxial system. The display screen 1, semi-transmissive semi-reflective mirror 7, and second lens 5 are sequentially distributed along the axis direction of the semi-transmissive semi-reflective mirror 7, simplifying the optical path, reducing optical distortion, improving image quality and stability, and being easy to calibrate and maintain.

[0036] The display screen 1 is used to emit light rays and display images. The display screen 1 can be a liquid crystal display (LCD), an organic light-emitting diode (OLED) screen, a silicon-based OLED screen, a silicon-based LED screen, or other display devices that can provide images. In some embodiments, the display screen 1 is single green display. Single green display means that all contents are presented in green tones and are generally monochromatic (without gray scale or color change). The single green display screen can provide higher contrast and visibility, and at the same time has characteristics such as low energy consumption and reduced eye fatigue of users.

[0037] In some embodiments, the display height range of the display screen 1 is 0.5 mm to 10 mm, meeting the requirements of small size and lightweight of the display module 100.

[0038] In this embodiment, the first polarizing element 2 can be used to modulate the light rays emitted by the display screen 1 into first circularly polarized light 101. Among them, the first polarizing element 2 can be a transmissive polarizing element. For example, the first polarizing element 2 can be a circular polarizer. The light rays emitted by the display screen 1 can form first circularly polarized light 101 after being modulated by the circular polarizer. Optionally, the first polarizing element 2 is attached to the surface of the display screen 1, which can reduce external light reflection, filter unnecessary light rays, enhance the contrast and readability of the screen image, and improve the visual experience.

[0039] Optionally, the first circularly polarized light 101 generated by modulation via the first polarizer 2 may be left-handed circularly polarized light or right-handed circularly polarized light. It should be noted that left-handed circularly polarized light means that when observing the polarized light facing the light wave, the polarization direction of the polarized light rotates counterclockwise; right-handed circularly polarized light means that when observing the polarized light facing the light wave, the polarization direction of the polarized light rotates clockwise.

[0040] In this embodiment, the semi-transparent and semi-reflective mirror 7 includes a semi-transparent and semi-reflective film 3 and a first lens 4, as Figure 1 and Figure 2 shown. The semi-transparent and semi-reflective film 3 (Semi-transparent and semi-reflective membrane) is a film layer structure with a transmittance and a reflectance of 50% each. That is, when light passes through the semi-transparent and semi-reflective film 3, 50% of the light will pass through the semi-transparent and semi-reflective film 3 and exit, and 50% of the light will be reflected by the semi-transparent and semi-reflective film 3.

[0041] As Figure 1 shown, the first lens 4 is a lens close to the display screen 1. The first surface 41 of the first lens 4 is the surface close to the first polarizer 2, and the second surface 42 of the first lens 4 is the surface far from the first polarizer 2. The semi-transparent and semi-reflective film 3 is disposed on the first surface 41 of the first lens 4 or the second surface 42 of the first lens 4 to form the semi-transparent and semi-reflective mirror 7. The first lens 4 can be used to support the semi-transparent and semi-reflective film 3, so that the light emitted by the display screen 1 can be reflected and refracted multiple times between the semi-transparent and semi-reflective film 3 and the light guide assembly 6, thereby realizing the folding optical path scheme.

[0042] In some embodiments, the above semi-transparent and semi-reflective film 3 can be deposited on the first surface 41 of the first lens 4 or the second surface 42 of the first lens 4 through a coating process. Among them, the distance between the semi-transparent and semi-reflective film 3 and the display screen 1 ≥ 0.1 mm, which can ensure good optical performance, reduce unnecessary interference and distortion, and at the same time meet the mechanical structure requirements, ultimately improving the overall user experience. Of course, the selection of specific values also needs to be adjusted according to the actual application scenario and technical requirements. It should be noted that Figure 1 shows a schematic diagram of the semi-transparent and semi-reflective film 3 deposited on the first surface 41 of the first lens 4.

[0043] As Figure 1As shown in the figure, the second lens 5 is the lens away from the display screen 1. The third surface 51 of the second lens 5 is the surface close to the first polarizer 2 and the semi-transmissive semi-reflective mirror 7, and the fourth surface 52 of the second lens 5 is the surface away from the first polarizer 2. The light guide assembly 6 is disposed on the fourth surface 52 of the second lens 5. The second lens 5 can be used to support the light guide assembly 6, so that the light emitted by the display screen 1 can be reflected and refracted multiple times between the semi-transmissive semi-reflective film 3 and the light guide assembly 6, thereby realizing the folding optical path scheme and ensuring the normal transmission of light. The light guide assembly 6 is disposed on the fourth surface 52 of the second lens 5, which can significantly improve the display effect and user experience of the AR or VR system, improve the optical efficiency, enhance the visual comfort and image quality.

[0044] In some embodiments, the first surface 41 of the first lens 4 is a convex surface, the second surface 42 of the first lens 4 is a concave surface, the third surface 51 of the second lens 5 is a convex surface, and the fourth surface 52 of the second lens 5 is a concave surface. Among them, the second surface 42 of the first lens 4 and the third surface 51 of the second lens 5 are adjacent, that is, the concave surface and the convex surface are adjacent, which can significantly improve the optical performance, including advantages such as aberration correction, light efficiency improvement, design simplification, precise optical path control, and increased depth of focus. At the same time, it can also reduce the volume of the display module 100 and achieve miniaturization and light weight.

[0045] Each surface of the first lens 4 and the second lens 5 in the display module 100 can be set as a curved surface, and this curved surface structure can better correct the aberration distortion and improve the imaging quality of the entire display module 100.

[0046] In this embodiment, the first lens 4 and the second lens 5 are spherical mirrors, that is, both the concave surface and the convex surface are spherical surfaces, which are easy to process. The material is the most common glass, and the cost is low.

[0047] In some embodiments, the fourth surface 52 of the second lens 5 is relatively flat, a concave surface close to a plane, that is, a spherical surface with a large curvature, which can avoid stretching the light guide assembly 6. It can not only improve the installation yield of the light guide assembly 6 (quarter-wave plate 61), but also ensure that the modulation transfer function (MTF) is close to the diffraction limit and ensure the optical performance of the display module 100. Optionally, the absolute value of the radius of curvature of the fourth surface 52 of the second lens 5 is greater than 25 mm.

[0048] In some embodiments, the absolute value of the radius of curvature of the first surface 41 is greater than 10 mm, the absolute value of the radius of curvature of the second surface 42 is greater than 5 mm, the absolute value of the radius of curvature of the third surface 51 is greater than 6 mm, the thickness range of the first lens 4 is 0.2 mm to 3 mm, and the thickness range of the second lens 5 is 0.3 mm to 2.5 mm. The refractive index range of the first lens 4 and the second lens 5 is 1.5 to 2.0, and the dispersion range of the first lens 4 and the second lens 5 is 20 to 70. The first lens 4 and the second lens 5 with the above parameters enable the optical total length of the display module 100 to be ≤ 6 mm, which can meet the requirements of miniaturization and light weight. At the same time, it can also ensure that the MTF is close to the diffraction limit, resulting in a small range of aberration distortion and improving the imaging quality of the entire display module 100. The optical total length refers to the distance between the fourth surface 52 of the second lens 5 and the display screen 1.

[0049] In some embodiments, the light guide assembly 6 includes a quarter-wave plate 61 and a second polarizer 62. The quarter-wave plate 61 is located between the second polarizer 62 and the fourth surface 52, as Figure 1 shown. Among them, the quarter-wave plate 61 can modulate the polarization state of light through the principle of phase delay, that is, convert linearly polarized light into circularly polarized light, or convert circularly polarized light into linearly polarized light. The quarter-wave plate 61 can improve the image quality and reduce unnecessary reflections.

[0050] Exemplarily, in the scenario where the above-mentioned first circularly polarized light 101 is left-handed circularly polarized light and the half-transmissive and half-reflective film 3 is coated on the first surface 41 of the first lens 4, the propagation process of the light path in the display module 100 is as follows: The light emitted by the display screen 1 is modulated into the first circularly polarized light 101 by the first polarizer 2. The first circularly polarized light 101 sequentially passes through the half-transmissive and half-reflective film 3, the first lens 4, and the second lens 5 and enters the quarter-wave plate 61, and is modulated into the first linearly polarized light by the quarter-wave plate 61. The first linearly polarized light is reflected by the second polarizer 62 to form a reflected linearly polarized light. The reflected linearly polarized light is modulated into the second circularly polarized light 102 by the quarter-wave plate 61. The second circularly polarized light 102 sequentially passes through the second lens 5, the first lens 4, and the half-transmissive and half-reflective film 3, and is reflected by the half-transmissive and half-reflective film 3 into the third circularly polarized light 103. The third circularly polarized light 103 passes through the first lens 4 and the second lens 5 and enters the quarter-wave plate 61, and is modulated into the second linearly polarized light by the quarter-wave plate 61. The second linearly polarized light is emitted from the second polarizer 62 to the human eye.

[0051] As Figure 2As shown, the polarization direction of the first circularly polarized light 101 is different from that of the third circularly polarized light 103. It can be understood that based on the principle of the folded optical path of the optical system, when the polarization direction of the first circularly polarized light 101 is different from that of the third circularly polarized light 103, it can ensure that the polarization direction of the light finally entering the human eye is the same as that of the light initially emitted by the display screen 1, so as to ensure that the image displayed on the display screen 1 can be normally transmitted to the human eye.

[0052] Exemplarily, after the circularly polarized light is reflected, the propagation direction of the light may change, and further, the polarization direction of the circularly polarized light may also change. For example, when the polarization direction of the first circularly polarized light 101 is clockwise, the polarization direction of the third circularly polarized light 103 is counterclockwise; that is, when the first circularly polarized light 101 is a right-handed circularly polarized light, the third circularly polarized light 103 is a left-handed circularly polarized light. When the polarization direction of the first circularly polarized light 101 is counterclockwise, the polarization direction of the third circularly polarized light 103 is clockwise; that is, when the first circularly polarized light 101 is a left-handed circularly polarized light, the third circularly polarized light 103 is a right-handed circularly polarized light.

[0053] As Figure 2 As shown, the polarization direction of the first linearly polarized light is different from that of the second linearly polarized light. It can be understood that based on the principle of the folded optical path, when the polarization direction of the first linearly polarized light is different from that of the second linearly polarized light, it can ensure that the polarization direction of the light finally entering the human eye is the same as that of the light initially emitted by the display screen 1, so as to ensure that the image displayed on the display screen 1 can be normally transmitted to the human eye.

[0054] In some embodiments, the polarization direction of the above-mentioned first linearly polarized light is perpendicular to the optical axis direction of the second polarizing member 62. That is, the first linearly polarized light can be a vertically linearly polarized light perpendicular to the optical axis direction of the second polarizing member 62. The polarization direction of the second linearly polarized light is horizontal with respect to the optical axis direction of the second polarizing member 62. That is, the second linearly polarized light can be a horizontally linearly polarized light horizontal with respect to the optical axis direction of the second polarizing member 62.

[0055] In some embodiments, the above-mentioned second polarizing member 62 can be a reflective polarizing member. Exemplarily, the above-mentioned reflective polarizing member can be a reflective polarizing film. Among them, the reflective polarizing film can reflect linearly polarized light perpendicular to its own optical axis direction and transmit linearly polarized light parallel to its own optical axis.

[0056] In a possible example, the first polarizing member 2 described above is a circular polarizer, and the second polarizing member 62 is a reflective polarizer. The first circularly polarized light 101 generated by the circular polarizer modulation is left-handed circularly polarized light. Exemplarily, in the scenario where the first circularly polarized light 101 is left-handed circularly polarized light, the propagation process of the light path in the display module 100 is as follows: The light emitted by the display screen 1 is modulated by the circular polarizer into left-handed circularly polarized light. The left-handed circularly polarized light passes through the semi-transmissive and semi-reflective film 3, the first lens 4, and the second lens 5 and enters the quarter-wave plate 61, where it is modulated into vertically polarized light by the quarter-wave plate 61. The vertically polarized light is reflected by the reflective polarizer to form reflected linearly polarized light. The reflected linearly polarized light is modulated by the quarter-wave plate 61 into left-handed circularly polarized light. The left-handed circularly polarized light passes through the second lens 5 and the first lens 4 and reaches the semi-transmissive and semi-reflective film 3. The left-handed circularly polarized light is reflected by the semi-transmissive and semi-reflective film 3 into right-handed circularly polarized light. The right-handed circularly polarized light passes through the first lens 4 and the second lens 5 and enters the quarter-wave plate 61, where it is modulated into horizontally polarized light by the quarter-wave plate 61. The horizontally polarized light is emitted through the reflective polarizer and transmitted to the human eye.

[0057] In another possible example, the first polarizing member 2 described above is a circular polarizer, and the second polarizing member 62 is a reflective polarizer. The first circularly polarized light 101 generated by the circular polarizer modulation is right-handed circularly polarized light. Exemplarily, in the scenario where the first circularly polarized light 101 is right-handed circularly polarized light, the propagation process of the light path in the display module 100 is as follows: The light emitted by the display screen 1 is modulated by the circular polarizer into right-handed circularly polarized light. The right-handed circularly polarized light passes through the semi-transmissive and semi-reflective film 3, the first lens 4, and the second lens 5 and enters the quarter-wave plate 61, where it is modulated into vertically polarized light by the quarter-wave plate 61. The vertically polarized light is reflected by the reflective polarizer to form reflected linearly polarized light. The reflected linearly polarized light is modulated by the quarter-wave plate 61 into right-handed circularly polarized light. The right-handed circularly polarized light passes through the second lens 5 and the first lens 4 and reaches the semi-transmissive and semi-reflective film 3. The right-handed circularly polarized light is reflected by the semi-transmissive and semi-reflective film 3 into left-handed circularly polarized light. The left-handed circularly polarized light passes through the first lens 4 and the second lens 5 and enters the quarter-wave plate 61, where it is modulated into horizontally polarized light by the quarter-wave plate 61. The horizontally polarized light is emitted through the reflective polarizer and transmitted to the human eye.

[0058] In some embodiments, the exit pupil distance range of the display module 100 is 8 mm to 20 mm, and the entire visual field can be seen completely. The exit pupil distance refers to the position from the fourth surface 52 of the second lens 5 to the human eye. A longer exit pupil distance allows the eyes to obtain a clear visual field without getting too close to the lens, which increases the viewing comfort.

[0059] The following is a specific simulation example of a display module 100. Among them, the exit pupil distance of the display module 100 is 15 mm, the wavelength range is 0.515 um to 0.541 um, the field of view angle is 10°, the display screen 1 is a single green screen, the pixel size is 4 um, the Nyquist cut-off frequency is 125 lp / mm, and the total optical length is 4.9 mm, which is smaller than the existing optical engine products on the market. The display module 100 uses a total of two lenses, and the lens surfaces are all spherical, which are very easy to process; the material selected is the most common H-K9L from Chengdu Guangming, and the price is low.

[0060] The specific parameter settings of the display module 100 are shown in Table 1:

[0061] Table 1 Parameter Table

[0062] Type Radius of curvature Fourth surface -36.1 Third surface -8.2 Second surface -5.6 First surface -14.4

[0063] Figure 3 It is a two-dimensional structure diagram of the optical path simulation of the display module 100, which can clearly reflect the propagation path of the optical path. Figure 4 It is the simulation MTF curve graph of the display module 100. From Figure 4 it can be seen that the MTF of the display module 100 is close to the diffraction limit, and the overall value is above 0.5. The large MTF value indicates good clarity and contrast. Figure 5 It is the simulation spot diagram of the display module 100. The circles are Airy disks, and the light spots are all within the Airy disks. This indicates that the display module 100 has excellent imaging performance and resolution ability. Various aberrations (such as spherical aberration, coma, astigmatism, etc.) have been effectively corrected or minimized. The fact that all the light spots are located within the Airy disks means that the influence of these aberrations on the imaging quality is extremely small. Figure 6 It is the simulation distortion curve graph of the display module 100. From Figure 6 it can be seen that the geometric distortion is within the range of 0.03%, which is very small, indicating that the display module 100 performs excellently in reducing image distortion and can provide accurate, clear and undistorted images.

[0064] The embodiment of the present application also provides an electronic device. The electronic device includes a device housing, a circuit board, and the above-mentioned display module 100. Among them, the circuit board is arranged inside the device housing, and the display module 100 is arranged on the device housing and connected to the circuit board, so that the user can obtain an image.

[0065] In some embodiments, the electronic device includes ordinary glasses or myopia glasses, etc. The frame 104 can be used as the device housing of the glasses, and the frame 104 is located outside the lens 105. Due to the characteristics of the above-mentioned display module 100, such as small volume and long exit pupil distance, the display module 100 can be placed in the frame 104, so that the image can be directly projected into the human eye, as Figure 7 shown.

[0066] Exemplarily, the electronic device may also be a mobile phone, a computer, an augmented reality (AR) / virtual reality (VR) device, etc., and the embodiments of the present application do not make specific limitations.

[0067] The embodiments of the present application provide a display module that does not need to be paired with a waveguide and can directly enter the eyes. While ensuring small size and light weight, it has high image quality, a suitable field of view (FOV), and is more similar to the form of glasses, which can improve the comfort and experience of users when wearing AR glasses.

[0068] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A display module, characterized in that, The display module (100) includes a display screen (1), a first polarizer (2), a semi-transmissive semi-reflective mirror (7), a second lens (5), and a light guide assembly (6) arranged in sequence. The light guide assembly (6) is disposed on a fourth surface (52) of the second lens (5), and the fourth surface (52) of the second lens (5) is a surface away from the first polarizer (2). Light emitted by the display screen (1) is modulated by the first polarizer (2) into a first circularly polarized light (101). The first circularly polarized light (101) passes through the semi-transmissive semi-reflective mirror (7) and the second lens (5) and enters the light guide assembly (6). After being modulated and reflected by the light guide assembly (6), a second circularly polarized light (102) is formed. The second circularly polarized light (102) passes through the second lens (5) and enters the semi-transmissive semi-reflective mirror (7), and is reflected by the semi-transmissive semi-reflective mirror (7) into a third circularly polarized light (103). The third circularly polarized light (103) passes through the second lens (5) and is emitted through the light guide assembly (6).

2. The display module according to claim 1, wherein The fourth surface (52) of the second lens (5) is a concave surface, and the absolute value of the radius of curvature of the fourth surface (52) is greater than 25 mm.

3. The display module according to claim 1, wherein The third surface (51) of the second lens (5) is a convex surface, and the third surface (51) is a surface close to the first polarizer (2).

4. The display module according to any one of claims 1 to 3, characterized in that The semi-transmissive semi-reflective mirror (7) includes a first lens (4) and a semi-transmissive semi-reflective film (3). The semi-transmissive semi-reflective film (3) is disposed on a first surface (41) or a second surface (42) of the first lens (4). The first surface (41) of the first lens (4) is a surface close to the first polarizer (2), and the second surface (42) of the first lens (4) is a surface away from the first polarizer (2).

5. The display module according to claim 4, wherein The first surface (41) of the first lens (4) is a convex surface, and the second surface (42) of the first lens (4) is a concave surface.

6. The display module according to claim 4, wherein The thickness range of the first lens (4) is 0.2 mm to 3 mm, the thickness range of the second lens (5) is 0.3 mm to 2.5 mm, the refractive index range of the first lens (4) and the second lens (5) is 1.5 to 2.0, and the dispersion range of the first lens (4) and the second lens (5) is 20 to 70.

7. The display module according to claim 4, wherein The first polarizer (2) is disposed on the surface of the display screen (1), and the distance between the semi-transmissive semi-reflective film (3) and the display screen (1) is ≥ 0.1 mm.

8. The display module according to claim 1, wherein The light guide assembly (6) includes a quarter-wave plate (61) and a second polarizer (62), and the quarter-wave plate (61) is located between the second polarizer (62) and the fourth surface (52). The light emitted by the display screen (1) is modulated into a first circularly polarized light (101) by the first polarizing element (2). The first circularly polarized light (101) passes through the semi-transmissive and semi-reflective mirror (7) and the second lens (5) and enters the quarter-wave plate (61). After being modulated into a first linearly polarized light by the quarter-wave plate (61), it is reflected by the second polarizing element (62) to the quarter-wave plate (61), and then modulated into a second circularly polarized light (102) by the quarter-wave plate (61). Then it is reflected by the semi-transmissive and semi-reflective mirror (7) into a third circularly polarized light (103), and enters the quarter-wave plate (61). After being modulated into a second linearly polarized light by the quarter-wave plate (61), it is emitted through the second polarizing element (62).

9. The display module according to claim 8, wherein The polarization direction of the first linearly polarized light is different from that of the second linearly polarized light. The polarization direction of the first circularly polarized light (101) is different from that of the third circularly polarized light (103). The first linearly polarized light is a vertical linearly polarized light perpendicular to the optical axis direction of the second polarizing element (62), and the second linearly polarized light is a horizontal linearly polarized light parallel to the optical axis direction of the second polarizing element (62).

10. An electronic device, characterized in that, The electronic device includes: A device housing and a circuit board, and the circuit board is arranged inside the device housing; The display module (100) according to any one of claims 1 to 9, which is arranged on the device housing and connected to the circuit board.

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