Optical Module and Head-Mounted Display Device

Abstract

Embodiments of the present application disclose an optical module and a head-mounted display device; the optical module includes a first lens and a diopter lens; the optical module further includes a beam splitter element, a first phase retarder, and a polarization reflection element, and the first phase retarder is located between the beam splitter element and the polarization reflection element; wherein, the beam splitter element and the first phase retarder are located on either side of the first lens, the polarization reflection element is disposed on any surface of the diopter lens, the diopter lenses are provided in multiple numbers according to different thicknesses, and are provided with multiple adjustable diopters according to different thicknesses, and the thickness and the adjustable diopter are in one-to-one correspondence, and the diopter of the optical module can be adjusted by inserting diopter lenses with different thicknesses into the optical module. The optical module of the embodiments of the present application is an optical structure with adjustable diopter, and can match user groups with different diopters by replacing diopter lenses with different thicknesses.

Description

Technical Field

[0001] This application belongs to the technical field of optical display, and specifically, this application relates to an optical module and a head-mounted display device. Background Art

[0002] The working principle of a virtual reality (VR) device is that the image displayed by the display is transmitted and magnified by a series of optical devices, and then the image is received by the human eye, and the human eye observes a magnified virtual image. In the field of virtual reality, the near-eye display module, as a core optical device, provides image display for users. However, the current near-eye display device is an optical module with a fixed diopter and does not support myopia adjustment, so that myopic users can only clearly view the picture when wearing glasses. Summary of the Invention

[0003] The purpose of the embodiments of this application is to provide a new technical solution for an optical module and a head-mounted display device.

[0004] According to the first aspect of the embodiments of this application, an optical module is provided. The optical module includes a first lens and a diopter lens;

[0005] The optical module further includes a beam splitter element, a first phase retarder, and a polarization reflection element. The first phase retarder is located between the beam splitter element and the polarization reflection element;

[0006] Wherein, the beam splitter element and the first phase retarder are located on either side of the first lens, the polarization reflection element is disposed on either surface of the diopter lens, the diopter lenses are provided in multiple numbers according to different thicknesses, and are provided with multiple adjustable diopters according to different thicknesses. The thickness and the adjustable diopter are in one-to-one correspondence. By inserting diopter lenses with different thicknesses in the optical module, the diopter of the optical module can be adjusted.

[0007] Optionally, the thickness of the diopter lens is 2 mm to 4.5 mm.

[0008] Optionally, the polarization reflection element is disposed on the surface of the diopter lens close to the first lens;

[0009] The distance between the center of the diopter lens and the center of the first lens is L1, and L1 satisfies: 4 mm < L1 < 7 mm.

[0010] Optionally, the optical module further includes a polarizing element. The polarizing element is disposed on one surface of the diopter lens, and the polarization reflection element is located between the first phase retarder and the polarizing element.

[0011] Optionally, the optical module further includes a second lens, which is located on the side of the diopter lens away from the first lens.

[0012] Optionally, the optical module further includes a polarizing element, which is disposed on the surface of the second lens close to the diopter lens.

[0013] Optionally, the optical module further includes a display, which is located on the side of the first lens away from the diopter lens.

[0014] Optionally, the beam splitting element is disposed on the surface of the first lens close to the display, and the first phase retarder is disposed on the surface of the first lens away from the display.

[0015] Optionally, the focal length of the second lens is f2, the focal length of the first lens is f1, and the focal length of the optical module is f, and the three satisfy: f2 > f1 > 6f.

[0016] Optionally, the focal length of the optical module is f, and f satisfies: 28 mm to 30 mm.

[0017] Optionally, the central thickness of the second lens is T2, and T2 satisfies: 3 mm < T2 < 6 mm; the distance between the center of the second lens and the center of the diopter lens is 0.3 mm to 1 mm.

[0018] Optionally, the distance between the first lens and the display is L2, and L2 satisfies: 3 mm < L2 < 5 mm.

[0019] Optionally, the display is configured to be capable of emitting circularly polarized light or linearly polarized light;

[0020] When the light emitted by the display is linearly polarized light, a second phase retarder is disposed between the display and the first lens, and the second phase retarder is used to convert the linearly polarized light into circularly polarized light.

[0021] Optionally, the central thickness of the first lens is T1, and T1 satisfies: 6 mm < T1 ≤ 8 mm.

[0022] According to the second aspect of the embodiments of the present application, there is also provided a head-mounted display device, including:

[0023] A housing; and

[0024] The optical module as described above.

[0025] According to the optical module of the embodiment of the present application, by providing the optical module with a plurality of visibility lenses of different thicknesses and setting a plurality of adjustable visibilities accordingly according to different thicknesses, when the user uses the optical module, the adjustment of the focal length of the optical module can be achieved only by replacing the visibility lenses of different thicknesses, so that the visibility of the optical module can be adjusted, thus matching different user groups with different myopia degrees, enabling myopic users with different visibilities to obtain a clear viewing effect without wearing glasses.

[0026] Other features and advantages of the present application will become clear through the following detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present application and, together with the description, are used to explain the principles of the present application.

[0028] Figure 1 One of the schematic structural diagrams of the optical module provided by the embodiment of the present application;

[0029] Figure 2 Another schematic structural diagram of the optical module provided by the embodiment of the present application;

[0030] Figure 3 Another schematic structural diagram of the optical module provided by the embodiment of the present application;

[0031] Figure 4 Schematic structural diagram of the optical module provided by Embodiment 1 of the present application;

[0032] Figure 5 For Figure 4 Spot diagram of the optical module shown;

[0033] Figure 6 Schematic structural diagram of the optical module provided by Embodiment 2 of the present application;

[0034] Figure 7 For Figure 6 Spot diagram of the optical module shown;

[0035] Figure 8 Schematic structural diagram of the optical module provided by Embodiment 3 of the present application;

[0036] Figure 9 For Figure 8 Spot diagram of the optical module shown.

[0037] Description of the reference numerals:

[0038] 10. First lens; 20. Second lens; 30. Diopter lens; 40. Beam splitter; 50. First phase retarder; 60. Polarization reflection element; 70. Polarizing element; 80. Display; 01. Human eye. Detailed implementation manners

[0039] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way limits the present application, its application, or its use.

[0041] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be regarded as part of the specification.

[0042] In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

[0043] It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0044] According to one aspect of the embodiments of the present application, an optical module is provided. The optical module is designed with a folded optical path optical structure and is suitable for use in a head-mounted display (HMD), such as a VR head-mounted device, such as a VR glasses or a VR helmet, etc. The embodiments of the present application do not make specific limitations thereto.

[0045] The embodiments of the present application provide an optical module, as Figures 1 to 3 shown, the optical module includes a first lens 10 and a diopter lens 30; the optical module further includes a beam splitter 40, a first phase retarder 50, and a polarization reflection element 60, and the first phase retarder 50 is located between the beam splitter 40 and the polarization reflection element 60;

[0046] Among them, the beam splitting element 40 and the first phase retarder 50 are located on either side of the first lens 10. The polarization reflection element 60 is disposed on either surface of the diopter lens 30. The diopter lenses 30 are provided in multiple numbers according to different thicknesses, and are provided with multiple adjustable diopters according to different thicknesses. The thickness and the adjustable diopter are in one-to-one correspondence. By inserting the diopter lenses 30 with different thicknesses into the optical module, the diopter of the optical module can be adjusted.

[0047] In an embodiment of the present application, a lens, that is, the first lens 10 described above, can be arranged in the optical module. At the same time, a diopter lens 30 that can be used to adjust the focal length of the optical module or can adjust the position of the virtual image is also introduced into the optical path. Among them, the diopter lens 30 can be flexibly arranged at a specified position in the optical path by means of insertion, for example, so as to be freely replaced in the optical path. The diopter lens 30 and the first lens 10 are located on the same optical axis, and the diopter lens 30 and the first lens 10 are adjacent and arranged at intervals.

[0048] In the optical solution of the embodiment of the present application, it is designed that the optical module is equipped with a plurality of replaceable diopter lenses 30 with different thicknesses. When applying the optical module, by replacing the diopter lens 30 with a corresponding thickness at a specified position in the optical path, the focusing of the optical module or the position of the formed virtual image can be adjusted. In this way, the diopter of the optical module is adjusted, and then the optical module can match user groups with different myopia degrees, so that myopic users can have a visual experience without wearing glasses.

[0049] For example, three diopter lenses 30 with different thicknesses are configured for the optical module, and these three diopter lenses 30 respectively correspond to three different diopters. When a user uses a product (such as a VR device) including this optical module, for users with different myopia degrees, such as: users with no myopia (diopter is 0), users with 400 degrees of myopia (diopter is -4D), users with 600 degrees of myopia (diopter is -6D), taking the users with 400 degrees of myopia as an example, when the users with 400 degrees of myopia have a visual experience, they only need to find the diopter lens 30 with a thickness matching this diopter and insert the diopter lens 30 into the specified position in the optical module, then they can view a clear picture without wearing glasses.

[0050] It should be noted that when the user's diopter does not match the thickness (or adjustable diopter) of the diopter lens 30 inserted in the optical module, it may occur that the image viewed by the user is not clear or is clear but the eyes are very tired (overcorrection). At this time, the user needs to replace the diopter lens 30 with a corresponding thickness according to their own diopter situation, so as to obtain a better viewing effect.

[0051] In the embodiment of the present application, the optical module can be provided with multiple diopter lenses 30. When using this optical module, a diopter lens 30 with a suitable thickness can be selected and inserted into a specified position in the optical module. That is to say, the user can find a diopter lens 30 with a thickness matching their own diopter among multiple alternative diopter lenses 30 according to their own diopter situation and then insert it into the optical module for use. In this way, a clear image can be viewed without wearing myopia glasses.

[0052] In the embodiment of the present application, as Figure 1 shown, the diopter lens 30 includes two opposite surfaces, namely the first surface P1S1 and the second surface P1S2. For example, it can be set that the first surface P1S1 faces the first lens 10, and at this time, the second surface P1S2 faces away from the first lens 10.

[0053] For example, the default state of the optical module is that a polarization reflection element 60 is attached to the first surface P1S1 of the diopter lens 30, and the polarization reflection element 60 faces away from the human eye 01. On this basis, by inserting diopter lenses 30 with different thicknesses into the optical module, the optical module can be made suitable for users with different myopia degrees to have a visual experience without wearing glasses.

[0054] In addition, it can also be that the polarization reflection element 60 is attached to the second surface P1S2 of the diopter lens 30, so that the polarization reflection element 60 faces the human eye 01. On this basis, by adjusting the thickness of the diopter lens 30 in the optical path, focusing of the optical module can also be achieved to suit different user groups with different diopters to have a visual experience without wearing glasses.

[0055] That is to say, in the embodiment of the present application, the polarization reflection element 60 is provided on one surface of the diopter lens 30. The user can only adjust the thickness of the diopter lens 30 inserted into the optical module to select visual experience scenarios with different myopia degrees and can view a clear imaging picture without wearing glasses.

[0056] In the embodiment of the present application, an optical module based on a folded optical path scheme is proposed. It is an optical module that realizes focusing by adjusting the thickness of the diopter lens 30 in the optical path. The focusing method proposed in the embodiment of the present application can meet different user groups with different myopia degrees. That is, the optical module supports different users with different myopia degrees to have a clear imaging visual experience without wearing glasses. All that needs to be done is to insert a diopter lens 30 that matches the user's diopter into the specified position in the optical module. The user can use it simply and conveniently and has a good experience.

[0057] The optical module according to the embodiment of the present application realizes the focusing of different diopters of the entire optical module by adjusting the thickness of the diopter lens 30 in the optical module. For example, three diopter lenses 30 with different thicknesses are provided for the optical module, and these three diopter lenses 30 correspond to three diopters of -0.5D, -4D, and -6D. In this way, the optical module can realize the focusing of at least one of -0.5D, -4D, and -6D.

[0058] In addition, by optimizing the surface shape of the lens in the optical module or increasing the number of optical elements, it is also possible to realize the focusing of diopters in the range of -0.5D to -8D or -5D to -8D, or even a larger diopter range. The embodiment of the present application does not limit this.

[0059] According to the embodiment of the present application, a folded optical path scheme is provided. By providing the optical module with a plurality of diopter lenses 30 of different thicknesses and setting a plurality of adjustable diopters according to different thicknesses, when the user uses the optical module, only by replacing the diopter lenses 30 of different thicknesses can the focusing of the optical module be adjusted, so that the diopter of the optical module can be adjusted. In this way, different user groups with different myopia degrees can be matched, so that myopic users with different diopters can obtain a clear viewing effect without wearing glasses.

[0060] The optical module provided by the embodiment of the present application has a good wearing experience for people with different degrees of myopia. Through the focusing scheme of the folded optical path, myopic users with different degrees can use the product including the optical module without wearing glasses. At the same time, the structure of the optical module is relatively simple, the manufacturing cost is low, and the yield is high.

[0061] In the embodiment of the present application, the materials of the first lens 10 and the diopter lens 30 are, for example, PMMA. Of course, the first lens 10 and the diopter lens 30 can also be other materials, such as glass materials, COC, COP and other materials. The embodiment of the present application does not limit this.

[0062] In addition, the materials of the first lens 10 and the diopter lens 30 can be the same or different. The embodiment of the present application does not limit this.

[0063] The optical module of the embodiment of the present application further includes a beam splitting element 40 and a first phase retarder 50.

[0064] Among them, the beam splitting element 40 allows a part of the light to pass through and a part of the light to be reflected.

[0065] The beam splitting element 40 is, for example, a semi-reflective semi-transmissive film.

[0066] The first phase retarder 50 can be used to change the polarization state of the light in the folded optical path structure. For example, it can convert linearly polarized light into circularly polarized light, or convert circularly polarized light into linearly polarized light.

[0067] The first phase retarder 50 is, for example, a quarter-wave plate.

[0068] Both the beam splitting element 40 and the first phase retarder 50 can be provided on either side of the first lens 10.

[0069] Optionally, the beam splitting element 40 and the first phase retarder 50 can be arranged at intervals, as Figures 1 to 3 shown, and are separated by the first lens 10 therebetween.

[0070] Of course, the beam splitting element 40 and the first phase retarder 50 can also be bonded together to form a laminated element, and the laminated element can be provided on any surface of the first lens 10 through an optical adhesive, or can be independently arranged in the optical path structure through a flat plate element, and the embodiments of the present application do not make specific limitations thereto.

[0071] It should be noted that the polarization reflection element 60 can be used to transmit P-polarized light and reflect S-polarized light; or, the polarization reflection element 60 can be used to transmit S-polarized light and reflect P-polarized light. The first phase retarder 50 and the polarization reflection element 60 cooperate to analyze light rays and transmit the light rays.

[0072] Among them, the polarization reflection element 60 can be a film-like structure, and it can be mounted on one surface of the diopter lens 30 through an optical adhesive. Figure 1 What is shown in the figure is mounted on the first surface P1S1 of the diopter lens 30. Of course, it can also be arranged on the second surface P1S2, and no limitation is made thereto.

[0073] Optionally, antireflection films can be provided on the surface of the first lens 10 where the first phase retarder 50 is provided, and on the two surfaces of the diopter lens 30. The antireflection film can be used to increase the transmitted light and reduce the reflected light.

[0074] The optical module of the embodiment of the present application is a folded optical path optical structure design. As Figures 1 to 3 shown, each optical lens and optical element in the optical module can be arranged in a set manner and located on the same optical axis. The size of the entire optical path structure is small and does not occupy a large space.

[0075] In some examples of the present application, the thickness of the diopter lens 30 is, for example, in the range of 2 mm to 4.5 mm.

[0076] That is to say, within the thickness range of the diopter lens 30, multiple diopter lenses 30 can be provided, each diopter lens 30 has a corresponding thickness, and at the same time, there is a corresponding adjustable diopter at this thickness. Designing the thickness of the diopter lens 30 within the above range in the embodiments of the present application can meet the needs of most myopic users.

[0077] Of course, a special thickness of the diopter lens 30 can also be designed according to specific circumstances to meet the needs of myopic users who require higher diopter.

[0078] In some examples of this application, such as Figures 1 to 3 As shown, the polarized reflective element 60 is disposed on the surface of the diopter lens 30 close to the first lens 10 ; the distance between the center of the diopter lens 30 and the center of the first lens 10 is L1 , and L1 satisfies: 4mm<L1<7mm.

[0079] In the embodiments of the present application, Figure 1 As shown, the polarized reflective element 60 can be disposed on the first surface P1S1 of the diopter lens 30. At this time, the polarized reflective element 60 is facing the first lens 10 and away from the human eye 01. For example, different diopter lenses 30 with a thickness ranging from 2mm to 4.5mm are inserted in the optical path, and the distance between the center of the diopter lens 30 and the center of the first lens 10 is adjusted to be within the range of 4mm to 7mm. In this way, the visual experience needs of users with different myopia levels can be met, and users can see clear and complete images without wearing glasses. Moreover, the optical module also has the characteristics of small size, which can improve the wearing comfort of users.

[0080] In some examples of this application, such as Figures 1 to 3 As shown, the optical module further includes a polarizing element 70 , which is disposed on a surface of the diopter lens 30 , and the polarizing reflective element 60 is located between the first phase retarder 50 and the polarizing element 70 .

[0081] In the present application embodiment, Figure 1 As shown, the optical module may further include a polarizing element 70, which can transmit P-polarized light, thereby reducing ghost images and stray light, and improving imaging quality.

[0082] The polarizing element 70 and the polarizing reflecting element 60 may be arranged at an interval.

[0083] For example, the polarized reflective element 60 is disposed on the first surface P1S1 of the diopter lens 30 , and the polarizing element 70 is disposed on the second surface P1S2 of the diopter lens 30 .

[0084] Of course, the polarizing element 70 and the polarizing reflective element 60 can also be bonded together to form a superimposed element, and the superimposed element is disposed on the first surface P1S1 of the diopter lens 30 . However, it should be noted that the polarizing reflective element 60 should be located between the first phase retarder 50 and the polarizing element 70 .

[0085] In some examples of this application, such as Figures 1 to 3As shown, the optical module further includes a second lens 20, and the second lens 20 is located on a side of the diopter lens 30 away from the first lens 10.

[0086] The optical module according to the embodiment of the present application may include the above-mentioned first lens 10 and the second lens 20 newly introduced into the optical module. At this time, the diopter lens 30 supporting the polarization reflection element 60 can be disposed between the first lens 10 and the second lens 20 when inserted.

[0087] It should be noted that the number of lenses provided in the optical module provided in the present application may not be specifically limited, and the number of lenses may be one, two, or three or more. The imaging quality can be improved as the number of lenses increases.

[0088] Among them, it is more preferable to provide two lenses and one diopter lens 30 in the optical path. In this way, while ensuring the imaging quality of the optical module, the optical module can be made thinner and lighter.

[0089] Optionally, both the first lens 10 and the second lens 20 are plano-convex lenses.

[0090] For example, the first lens 10 includes two surfaces: the third surface L1S1 and the fourth surface L1S2 respectively; among them, the surface shape of the third surface L1S1 is convex, and the surface shape of the fourth surface L1S2 is flat. The curvature of the third surface L1S1 of the first lens 10 satisfies the following conditions:

[0091] 70 < abs(R_L1S1) < 105, ABS(Conic_L1S1) < 5.

[0092] For example, the second lens 20 includes two surfaces: the fifth surface L2S1 and the sixth surface L2S2 respectively; among them, the surface shape of the fifth surface L2S1 is flat, and the surface shape of the sixth surface L2S2 is convex. The curvature of the sixth surface L2S2 of the second lens 20 satisfies the following conditions:

[0093] 100 < abs(R_L2S2) < 140, ABS(Conic_L2S2) < 5.

[0094] Of course, the first lens 10 and the second lens 20 include but are not limited to the above-mentioned surface shapes, and the present application does not limit this in the embodiment.

[0095] In addition, the material of the lens in the optical module can be PMMA material. Of course, the lens can also be other materials such as glass, COC, COP, etc. The present application does not specifically limit this in the embodiment.

[0096] Among them, the diopter lens 30 can be, for example, a PMMA flat plate or a glass flat plate, etc. In addition, the diopter lens 30 can also be replaced with other shapes such as a plano-convex element, a plano-concave element, a biconcave element, a biconvex element, etc.

[0097] Optionally, when the optical module simultaneously includes the first lens 10, the second lens 20, and the diopter lens 30, the polarizing element 70 can be disposed on the surface of the second lens 20 close to the diopter lens 30.

[0098] That is to say, when the second lens 20 is introduced into the optical module, the polarizing element 70 can be mounted on the second lens 20, and the second lens 20 is used to support the polarizing element 70. The polarizing element 70 can transmit P-polarized light, can reduce ghost images and stray light, and is beneficial to improving the imaging quality.

[0099] Optionally, antireflection films can be respectively disposed on the two surfaces of the second lens 20 to increase transmission and reduce reflection, which is beneficial to improving the imaging quality.

[0100] In some examples of the present application, as Figures 1 to 3 shown, the optical module further includes a display 80, and the display 80 is located on the side of the first lens 10 away from the diopter lens 30.

[0101] Optionally, the display 80 is configured to be capable of emitting circularly polarized light or linearly polarized light; when the light emitted by the display 80 is linearly polarized light, a second phase retarder is disposed between the display 80 and the first lens 10, and the second phase retarder is used to convert the linearly polarized light into circularly polarized light.

[0102] Among them, the display 80 has a light-emitting surface, and a screen protector can be mounted on the light-emitting surface of the display 80, for example.

[0103] Among them, the light emitted from the light-emitting surface of the display 80 can be linearly polarized light, or circularly polarized light or natural light, and the embodiments of the present application do not limit this.

[0104] In addition, when it is necessary to dispose a second phase retarder at the light-emitting surface of the display 80, a polarizing element (polarizing film) can be further introduced into the optical path. At this time, the second phase retarder and the newly introduced polarizing element can be stacked and disposed on the light-emitting surface of the display 80. Of course, the two can also be disposed at intervals. The second phase retarder is located between the newly introduced polarizing element and the light-emitting surface of the display 80.

[0105] It should be noted that when the light emitted from the light-emitting surface of the display 80 is circularly polarized light, the above-mentioned second phase retarder and the second polarizing element can be omitted. In this way, the optical module can be simplified.

[0106] In an embodiment of the present application, the size of the display 80 can be about 2.5 inches, for example. The FOV of the optical module can be about 100°, and can even be larger. The spot size of the entire field of view is <88um, and the imaging quality is high, which can match people with different myopia degrees.

[0107] In some examples of the present application, as Figures 1 to 3 shown, in the optical module, the beam splitting element 40 is disposed on the surface of the first lens 10 close to the display 80, and the first phase retarder 50 is disposed on the surface of the first lens 10 away from the display 80.

[0108] In an embodiment of the present application, the beam splitting element 40 and the first phase retarder 50 are both thin film structures, for example, and the two can be mounted on the first lens 10 by means of film sticking.

[0109] For example, the beam splitting element 40 and the first phase retarder 50 can be respectively mounted on two surfaces of the first lens 10.

[0110] Also for example, the beam splitting element 40 and the first phase retarder 50 can also be bonded together and then mounted on the third surface L1S1 or the fourth surface L1S2 of the first lens 10. The embodiments of the present application do not limit this.

[0111] It should be noted that the surface of the lens where the optical film is usually pasted can be designed as a plane. The method of pasting the optical film on a plane in the optical path can reduce the difficulty of mounting the optical film. Of course, it is also possible to use a curved surface / cylindrical surface for film sticking, etc. The embodiments of the present application do not make specific limitations on this.

[0112] In some examples of the present application, when the optical module includes the first lens 10, the second lens 20, and a diopter lens 30, the focal length of the second lens 20 is f2, the focal length of the first lens 10 is f1, and the focal length of the optical module is f. The three satisfy: f2 > f1 > 6f.

[0113] Among them, the diopter lens 30 itself has no converging or diverging ability.

[0114] For example, the focal length f of the optical module is 28 mm to 30 mm.

[0115] Among them, the focal length f2 of the second lens 20 is 213 mm, and the focal length of the first lens f1 is 196 mm. The optical module is applicable to groups with different diopters, and at the same time can ensure that the volume of the optical module is small and the imaging quality is good.

[0116] In some examples of the present application, the central thickness of the second lens 20 is T2, and T2 satisfies: 3 mm < T2 < 6 mm; the distance between the center of the second lens 20 and the center of the diopter lens 30 is 0.3 mm to 1 mm.

[0117] In the optical module of the embodiment of the present application, the distance between the second lens 20 and the diopter lens 30 can be set to 0.3 mm to 1 mm, which will not increase the size of the optical module, is conducive to realizing the thinning and lightening of the optical module, and can ensure the imaging quality at the same time.

[0118] For example, when the distance between the second lens 20 and the diopter lens 30 is 0.3 mm, the size of the optical module can be better reduced and better imaging quality can be ensured.

[0119] Among them, the size of the second lens 20 is relatively small, which is conducive to reducing the weight of the optical module.

[0120] In some examples of the present application, the distance between the first lens 10 and the display 80 is L2, and L2 satisfies: 3 mm < L2 < 5 mm.

[0121] Among them, the central thickness of the first lens 10 is T1, and T1 satisfies: 6 mm < T1 ≤ 8 mm.

[0122] In the embodiment of the present application, the sizes of the first lens 10 and the diopter lens 30 are both relatively small, and the distances between the first lens 10, the diopter lens 30 and the display 80 are also relatively small. These are conducive to reducing the size of the optical module, realizing the thinning and lightening of the final product, improving the comfort when the user wears it, and enabling better imaging quality at the same time.

[0123] Optionally, the FOV of the optical module of the embodiment of the present application is ≥ 100°.

[0124] In the optical module of the embodiment of the present application, the image displayed by the display 80 can be refracted and reflected through a folded optical path and magnified and then input into the human eye 01, and the human eye 01 can see the magnified virtual image.

[0125] The optical module of the embodiment of the present application can cooperate with a 2.4 or 2.5-inch Micro OLED / LCD display chip and can achieve a 100-degree field of view.

[0126] At the same time, the total optical length of the optical module of the embodiment of the present application is about 24 mm, the size of the optical module is small, and the imaging quality is good.

[0127] As Figure 1 shown, the light propagation path of the optical module of the embodiment of the present application is as follows:

[0128] The display 80 emits circularly polarized light. After the circularly polarized light passes through the third surface L1S1 of the first lens 10 close to the display 80, about 50% of the light is transmitted through the beam splitting element 40 and then transmitted to the second surface L1S2 through the first lens 10. After being converted by the first phase retarder 50, it becomes linearly polarized light. Then, after passing through the first surface P1S1 of the diopter lens 30, it is reflected by the polarization reflection element 60 and returns to the fourth surface L1S2 of the first lens 10. After passing through the first phase retarder 50, it becomes circularly polarized light again and returns to the third surface L1S1 of the first lens 10. After passing through the beam splitting element 40, a part of the light is reflected back to the first lens 10 and then reaches the fourth surface L1S2 of the first lens 10 again. After passing through the first phase retarder 50, it becomes linearly polarized light and then passes through the first surface P1S1 and the second surface P1S2 of the diopter lens 30 in sequence. Since after being reflected by the beam splitting element 40, the direction of this linearly polarized light is consistent with the transmission optical axis direction of the polarization reflection element 60, after passing through the polarizing element 70 on the second lens 20 after passing through the polarization reflection element 60, it is transmitted through the surface L2S2 of the second lens 20 and finally enters the human eye 01.

[0129] The following uses three embodiments to illustrate the optical module of the embodiment of the present application.

[0130] Embodiment 1

[0131] The optical module of this Embodiment 1, as Figure 4 shown, includes a display 80, a first lens 10, a diopter lens 30, and a second lens 20 arranged in sequence; the optical module further includes a beam splitting element 40, a first phase retarder 50, and a polarization reflection element 60;

[0132] Among them, the beam splitting element 40 is arranged on the third surface L1S1 of the first lens 10 close to the display 80, the first phase retarder 50 is arranged on the fourth surface L1S2 of the first lens 10 far from the display 80, the polarization reflection element 60 is arranged on the first surface P1S1 of the diopter lens 30, and the diopter lens 30 further has a second surface P1S2; the polarizing element 70 is arranged on the fifth surface L2S1 of the second lens 20 close to the display 80;

[0133] Among them, the thickness of the diopter lens 30 is 2 mm, and the distance L1 between the center of the diopter lens 30 and the center of the first lens 10 is 6.801 mm.

[0134] The virtual image distance formed by the optical module of this Embodiment 1 is 2000 mm, and it is suitable for people with -0.5 D (nearsightedness of 50 degrees) to view images without wearing glasses.

[0135] Table 1 shows the optical parameters of the optical module;

[0136] Table 1

[0137] Surf Type Radius Thickness GLASS ClearDiam MechDiam Conic 4th OBJ STANDARD Infinity -2000.000 2383.507 2383.507 0 0 STO STANDARD Infinity 13.000 2.000 2.000 0 0 2 EVENASPH 105.402 4.500 PMMA 20.000 21.000 -1.002 -1.424E-06 3 STANDARD Infinity 0.500 21.000 21.000 0 0 4 STANDARD Infinity 2.000 PMMA 27.600 27.600 0 0 0 6 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 7 EVENASPH -96.883 -6.974 MIRROR 29.800 29.800 -1.019 -1.838E-07 8 STANDARD Infinity -6.801 29.800 29.800 0 0 9 STANDARD Infinity 6.801 MIRROR 27.600 27.600 0 0 10 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 11 EVENASPH -96.883 4.000 29.800 29.800 -1.019 -1.838E-07 12 STANDARD Infinity 0.520 BK7 23.000 23.000 0 0 13 STANDARD Infinity 0.010 23.000 23.000 0 0 IMA STANDARD Infinity 0.000 22.800 22.800 0 0

[0138] The optical module provided in Embodiment 1, as Figure 5 shown, within the entire field of view of the optical module, the spot size value is less than 70 um.

[0139] Embodiment 2

[0140] The optical module of this Embodiment 2, as Figure 6 shown, includes a display 80, a first lens 10, a diopter lens 30, and a second lens 20 arranged in sequence; the optical module further includes a beam splitter element 40, a first phase retarder 50, and a polarization reflection element 60;

[0141] Among them, the beam splitter element 40 is disposed on the third surface L1S1 of the first lens 10 close to the display 80, and the first phase retarder 50 is disposed on the fourth surface L1S2 of the first lens 10 away from the display 80; the polarization reflection element 60 is disposed on the first surface P1S1 of the diopter lens 30, and the diopter lens 30 further has a second surface P1S2; the polarization element 70 is disposed on the fifth surface L2S1 of the second lens 20 close to the display 80;

[0142] Among them, the difference from Embodiment 1 is that:

[0143] The thickness of the diopter lens 30 is changed to 3.56 mm, and the distance L1 between the center of the diopter lens 30 and the center of the first lens 10 is adjusted to 5.24 mm.

[0144] The virtual image distance formed by the optical module of this Embodiment 2 is 250 mm, and it is suitable for people with -4D (nearsightedness of 400 degrees) to view images without wearing glasses.

[0145] Table 2 shows the optical parameters of the optical module;

[0146] Table 2

[0147] Surf Type Radius Thickness GLASS ClearDiam MechDiam Conic 4th OBJ STANDARD Infinity -250.000 297.938 297.938 0 0 STO STANDARD Infinity 13.000 2.000 2.000 0 0 2 EVENASPH 105.402 4.500 PMMA 20.000 21.000 -1.002 -1.424E-06 3 STANDARD Infinity 0.500 21.000 21.000 0 0 4 STANDARD Infinity 3.559 PMMA 27.600 27.600 0 0 5 STANDARD Infinity 5.242 27.600 27.600 0 0 6 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 7 EVENASPH -96.883 -6.974 MIRROR 29.800 29.800 -1.019 -1.838E-07 8 STANDARD Infinity -5.242 29.800 29.800 0 0 9 STANDARD Infinity 5.242 MIRROR 27.600 27.600 0 0 10 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 11 EVENASPH -96.883 4.000 29.800 29.800 -1.019 -1.838E-07 12 STANDARD Infinity 0.520 BK7 23.000 23.000 0 0 13 STANDARD Infinity 0.010 23.000 23.000 0 0 IMA STANDARD Infinity 0.000 22.800 22.800 0 0

[0148] The optical module provided in this Embodiment 2, as Figure 7 shown, within the entire field of view of the optical module, the spot size value is less than 53 um.

[0149] Embodiment 3

[0150] The optical module of this Embodiment 3, as Figure 8As shown, it includes a display 80, a first lens 10, a diopter lens 30, and a second lens 20 arranged in sequence; the optical module further includes a beam splitter 40, a first phase retarder 50, and a polarization reflection element 60;

[0151] Among them, the beam splitter 40 is arranged on the third surface L1S1 of the first lens 10 close to the display 80, and the first phase retarder 50 is arranged on the fourth surface L1S2 of the first lens 10 far from the display 80; the polarization reflection element 60 is arranged on the first surface P1S1 of the diopter lens 30, and the diopter lens 30 further has a second surface P1S2; the polarizing element 70 is arranged on the fifth surface L2S1 of the second lens 20 close to the display 80;

[0152] Among them, the difference from Embodiment 1 is that:

[0153] The thickness of the diopter lens 30 is replaced with 4.44 mm, and the distance L1 between the center of the diopter lens 30 and the center of the first lens 10 is adjusted to 4.36 m.

[0154] The virtual image distance formed by the optical module is 167 mm, which is suitable for people with -6D (nearsightedness of 600 degrees) to view images without wearing glasses.

[0155] Table 3 shows the optical parameters of the optical module;

[0156] Table 3

[0157] Surf Type Radius Thickness GLASS ClearDiam MechDiam Conic 4th OBJ STANDARD Infinity -166.000 197.831 197.831 0 0 STO STANDARD Infinity 13.000 2.000 2.000 0 0 2 EVENASPH 105.402 4.500 PMMA 20.000 21.000 -1.002 -1.424E-06 3 STANDARD Infinity 0.500 21.000 21.000 0 0 4 STANDARD Infinity 4.440 PMMA 27.600 27.600 0 0 5 STANDARD Infinity 4.361 27.600 27.600 0 0 6 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 7 EVENASPH -96.883 -6.974 MIRROR 29.800 29.800 -1.019 -1.838E-07 8 STANDARD Infinity -4.361 29.800 29.800 0 0 9 STANDARD Infinity 4.361 MIRROR 27.600 27.600 0 0 10 STANDARD Infinity 6.974 PMMA 29.800 29.800 0 0 11 EVENASPH -96.883 4.000 29.800 29.800 -1.019 -1.838E-07 12 STANDARD Infinity 0.520 BK7 23.000 23.000 0 0 13 STANDARD Infinity 0.010 23.000 23.000 0 0 IMA STANDARD Infinity 0.000 22.800 22.800 0 0

[0158] The optical module provided in this Embodiment 3, as Figure 8 shown, within the full field of view of the optical module, the spot size value is less than 88 um.

[0159] According to another aspect of the embodiments of the present application, there is also provided a head-mounted display device, which includes a housing and the optical module as described above.

[0160] The head-mounted display device is, for example, a VR head-mounted device, including VR glasses or a VR helmet, etc., and the embodiments of the present application do not make specific limitations thereto.

[0161] The specific implementation manners of the head-mounted display device in the embodiments of the present application can refer to the respective embodiments of the above display module, and will not be elaborated herein.

[0162] What was mainly described in the above embodiments is the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a more optimal embodiment. Considering the simplicity of the text, it will not be elaborated herein.

[0163] Although some specific embodiments of the present application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An optical module, characterized in that, It includes a first lens (10) and a diopter lens (30); The optical module further includes a beam splitting element (40), a first phase retarder (50) and a polarization reflection element (60), and the first phase retarder (50) is located between the beam splitting element (40) and the polarization reflection element (60); Wherein, the beam splitting element (40) and the first phase retarder (50) are located on either side of the first lens (10), the polarization reflection element (60) is disposed on any surface of the diopter lens (30), the diopter lens (30) is provided in multiple numbers according to different thicknesses, and is provided with multiple adjustable diopters according to different thicknesses, and the thickness and the adjustable diopter are in one-to-one correspondence. The diopter of the optical module can be adjusted by inserting the diopter lenses (30) with different thicknesses into the optical module; The polarization reflection element (60) is disposed on the surface of the diopter lens (30) close to the first lens (10); The distance between the center of the diopter lens (30) and the center of the first lens (10) is L1, and L1 satisfies: 4mm < L1 < 7mm; The thickness of the diopter lens (30) is 2mm to 4.5mm; The focal length of the optical module is f, and f satisfies: 28mm to 30mm.

2. The optical module according to claim 1, characterized in that, The optical module further includes a polarizing element (70), the polarizing element (70) is disposed on one surface of the diopter lens (30), and the polarization reflection element (60) is located between the first phase retarder (50) and the polarizing element (70).

3. The optical module according to claim 1, characterized in that, The optical module further includes a second lens (20), and the second lens (20) is located on the side of the diopter lens (30) away from the first lens (10).

4. The optical module according to claim 3, wherein The optical module further includes a polarizing element (70), and the polarizing element (70) is disposed on the surface of the second lens (20) close to the diopter lens (30).

5. The optical module according to any one of claims 1-4, characterized in that, The optical module further includes a display (80), and the display (80) is located on the side of the first lens (10) away from the diopter lens (30).

6. The optical module according to claim 5, characterized in that, The beam splitting element (40) is disposed on the surface of the first lens (10) close to the display (80), and the first phase retarder (50) is disposed on the surface of the first lens (10) away from the display (80).

7. The optical module according to claim 3, wherein The focal length of the second lens (20) is f2, the focal length of the first lens (10) is f1, and the focal length of the optical module is f. The three satisfy: f2 > f1 > 6f.

8. The optical module according to claim 3, wherein The central thickness of the second lens (20) is T2, and T2 satisfies: 3mm < T2 < 6mm; the distance between the center of the second lens (20) and the center of the diopter lens (30) is 0.3mm to 1mm.

9. The optical module according to claim 5, wherein, The distance between the first lens (10) and the display (80) is L2, and L2 satisfies: 3mm < L2 < 5mm.

10. The optical module according to claim 5, wherein, The display (80) is configured to be able to emit circularly polarized light or linearly polarized light; When the light emitted by the display (80) is linearly polarized light, a second phase retarder is disposed between the display (80) and the first lens (10), and the second phase retarder is used to convert the linearly polarized light into circularly polarized light.

11. The optical module according to claim 1, characterized in that, The central thickness of the first lens (10) is T1, and T1 satisfies: 6 mm < T1 ≤ 8 mm.

12. A head-mounted display device, characterized in that, Comprising: A housing; And An optical module according to any one of claims 1-11.

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