CN113934007A

CN113934007A - Optical module and head-mounted display device

Info

Publication number: CN113934007A
Application number: CN202111261089.3A
Authority: CN
Inventors: 孙琦
Original assignee: Goertek Optical Technology Co Ltd
Current assignee: Goertek Optical Technology Co Ltd
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2022-01-14
Also published as: WO2023070808A1

Abstract

The invention discloses an optical module and a head-mounted display device. The optical module includes a display that emits light for imaging display. The cemented lens is arranged in the light emitting direction of the display. The cemented lens includes a first lens and a second lens that are arranged in sequence along the direction away from the display. The Abbe number of the material of the first lens is different from the Abbe number of the material of the second lens. On the first surface, the flat element is arranged on the side of the second lens away from the first lens, the flat element has a fifth surface facing the second lens, and the fifth surface is sequentially attached with a quarter along the direction away from the second lens. Waveplates and polarizing reflectors. The technical solution of the present invention aims to reduce the volume of the head-mounted display device by reducing the total optical length of the optical system, which is convenient for users to wear, and at the same time ensures that the chromatic aberration value of the image after imaging is low, so as to reduce the display pixels of the image by the imaging software in the later stage. compensation pressure.

Description

Optical module and head-mounted display device

Technical Field

The invention relates to the technical field of optical display, in particular to an optical module and head-mounted display equipment using the same.

Background

With the development and upgrading of advanced optical design and processing technology, display technology and processors, the shapes and types of Virtual Reality (VR) products are infinite, and the application fields thereof are also increasingly wide. The main working principle of the virtual reality product is that after an image displayed by the display is transmitted and amplified through the optical lens, the image is received by human eyes, and the human eyes observe an amplified virtual image. In the related art, an image needs a sufficiently long optical path after being amplified, so that the total optical length of an optical system is long, which causes a head-mounted display device to have a large volume and to be inconvenient for a user to wear, and further causes a compensation pressure of post-imaging software on display pixels of the image to be large due to a high chromatic aberration of the imaged image.

Disclosure of Invention

The invention mainly aims to provide an optical module, which aims to reduce the volume of head-mounted display equipment by reducing the optical total length of an optical system, is convenient for a user to wear, and simultaneously ensures that the color difference value of an image after imaging is lower so as to reduce the compensation pressure of later imaging software on the display pixels of the image, improve the imaging quality and enable the imaging to be clearer.

To achieve the above object, the present invention provides an optical module, including:

a display that emits light for imaging display;

the cemented lens is arranged in the light outgoing direction of the display and comprises a first lens and a second lens which are sequentially arranged along the direction deviating from the display, the first lens is provided with a first surface facing the display and a second surface facing away from the display, the second lens is provided with a third surface facing the display and a fourth surface facing away from the display, the second surface and the third surface are arranged in a cemented manner, the direction of the second surface deviating from the display is convex, the direction of the third surface facing the display is concave, and the Abbe number of the material of the first lens is different from the Abbe number of the material of the second lens; and

the light splitting element is arranged on the first surface;

the flat component is arranged on one side, deviating from the first lens, of the second lens, the flat component is provided with a fifth surface facing the second lens, and a quarter-wave plate and a polarization reflection film are sequentially attached to the fifth surface along the direction deviating from the second lens.

Optionally, the optical module further includes a polarizing film disposed on a side of the polarizing reflective film facing away from the quarter-wave plate.

Optionally, the optical module further includes a first antireflection film, and the first antireflection film is disposed on a side of the quarter-wave plate away from the polarization reflection film.

Optionally, the first antireflection film, the quarter-wave plate, the polarization reflection film and the polarization film are all film layer structures, and the first antireflection film, the quarter-wave plate, the polarization reflection film and the polarization film are combined into an integral film layer.

Optionally, the flat plate element further has a sixth surface facing away from the second lens, and a second antireflection film is attached to the sixth surface.

Optionally, the fifth surface and the sixth surface of the plate element are both in a planar arrangement.

Optionally, if the radius value of the first surface is R1, the conic coefficient of the first surface is C1, the radius value of the second surface is R2, the conic coefficient of the second surface is C2, the radius value of the third surface is R3, the conic coefficient of the third surface is C3, and the radius value of the fourth surface is R4, the following are satisfied:

35mm≤R1≤60mm，150mm≤R2＝R3≤200mm；

C1＝C2＝C3≤20，150mm≤R4≤190mm。

optionally, distortion of the optical module is less than 19.4%, chromatic aberration of the optical module is less than 12 μm, field curvature of the optical module is less than 0.5mm, and a spot diameter of the optical module is less than 38.8 μm.

In addition, in order to solve the above problems, the present invention further provides a head-mounted display device, where the head-mounted display device includes a housing and the optical module as described above, the optical module is disposed on the housing, and the total optical length of the optical module in the horizontal direction is TTL1, and the total optical length of the optical module in the vertical direction is TTL2, then:

TTL1＜12mm，TTL2＜29mm。

in the technical scheme provided by the invention, the display emits light which is circularly polarized light. When the light rays irradiate the cemented lens, the light rays firstly pass through the light splitting element on the first surface of the first lens, one part of the light rays transmit the light splitting element, and the other part of the light rays are reflected. The light transmitted by the light splitting element sequentially emits to the second surface of the first lens, the third surface of the second lens and the fourth surface of the second lens, then the light transmitted by the fourth surface emits to the quarter-wave plate on the fifth surface of the flat plate element, at the moment, the polarization state of the circularly polarized light is changed, the circularly polarized light is converted into linearly polarized light, the linearly polarized light emits to the polarization reflection film again, at the moment, the vibration direction of the linearly polarized light is different from the transmission direction of the polarization reflection film and is reflected, the reflected light passes through the quarter-wave plate again, so that the linearly polarized light is converted into circularly polarized light again and is reflected by the second lens and the first lens sequentially, and when the light is reflected by the light splitting element again, part of the light is reflected and then passes through the first lens and the second lens of the lens assembly sequentially. The light is circularly polarized light, the rotating direction of the light is changed after the light is reflected, the light is converted into linearly polarized light again after passing through the quarter-wave plate, the polarization direction of the linearly polarized light is the same as the transmission direction of the polarization reflection film, and the light penetrates through the flat plate element and forms an image at the position of a human eye.

Therefore, the light rays are folded back at the flat plate element and the cemented lens, and are amplified and transmitted continuously in the whole process. The image magnifying device has the advantages that the image magnifying transmission is achieved in a limited space, the total optical length is favorably reduced, a user can conveniently wear the image magnifying device, the first lens and the second lens are made of different materials, different refractive indexes and abbe numbers are selected for matching, so that light is compensated to eliminate chromatic aberration when refraction occurs through the first lens and the second lens, the total optical length of an optical system can be reduced, the effect of low chromatic aberration is achieved, the compensating pressure of later-stage imaging software on display pixels of the image is reduced, the imaging quality is improved, and imaging is clearer. In addition, the quarter-wave plate and the polarization reflection film are arranged on the fifth surface of the flat panel element, so that the quarter-wave plate and the polarization reflection film are positioned on the inner side, close to the display, of the flat panel element, external scratches are prevented, reliability is improved, installation difficulty can be reduced, the quarter-wave plate and the polarization reflection film can be installed independently, and installation efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an optical module according to an embodiment of the present invention;

FIG. 2 is a schematic view of the flat plate member and lens assembly of the optical module of FIG. 1;

FIG. 3 is a schematic diagram of a partially enlarged structure of the optical module according to the present invention;

FIG. 4 is a dot-column diagram of the optical module of FIG. 1;

FIG. 5 is a graph of field curvature and distortion of the optical module of FIG. 1;

FIG. 6 is a color difference diagram of the optical module shown in FIG. 1.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Display device	31	Fifth surface
11	Light ray	31a	Quarter wave plate
				20	Lens assembly	31b	Polarizing reflective film
21	First lens	31c	Polarizing film
				211	First surface	31d	First antireflection film
212	Second surface	32	The sixth surface
				22	Second lens	32a	Second antireflection film
221	Third surface	32b	Hardened protective film
				222	The fourth surface	40	Light splitting element
30	Flat element	50	Human eye

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B," including either the A or B arrangement, or both A and B satisfied arrangement. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The display principle of the head-mounted display device also includes various display principles, for example, in addition to the VR display, an AR (Augmented Reality) display is included, the displayed image of the head-mounted display device needs to be transmitted and amplified through an optical lens, in the process of amplifying the image, a sufficient space is needed for transmitting light, the total optical length of an optical system is long, the head-mounted display device is large in size, inconvenient for a user to wear, and due to the fact that the imaged image has high chromatic aberration, the compensation pressure of the post-imaging software on the display pixel of the image is large.

In order to solve the above problems, the present invention provides an optical module.

Referring to fig. 1 to 3, in an embodiment of the present invention, an optical module includes: a display 10, a cemented lens 20, a light splitting element 40, and a flat panel element 30, the display 10 emitting light rays 11 for imaging display; the cemented lens 20 is arranged in the light outgoing direction of the display 10, the cemented lens 20 comprises a first lens 21 and a second lens 22 which are arranged in sequence along the direction away from the display 10, the first lens 21 has a first surface 211 facing the display 10 and a second surface 212 facing away from the display 10, the second lens 22 has a third surface 221 facing the display 10 and a fourth surface 222 facing away from the display 10, the second surface 212 and the third surface 221 are arranged in a cemented manner, the second surface 212 is convex in the direction away from the display 10, the third surface 221 is concave in the direction towards the display 10, and the abbe number of the material of the first lens 21 is different from that of the material of the second lens 22; the light splitting element 40 is arranged on the first surface 211; the flat plate element 30 is disposed on a side of the second lens 22 away from the first lens 21, the flat plate element 30 has a fifth surface 31 facing the second lens 22, and the quarter-wave plate 31a and the polarization reflection film 31b are sequentially attached to the fifth surface 31 along a direction away from the second lens 22.

Wherein the light rays 11 exiting through the display 10 have a circular polarization state. The light splitting element 40 may be disposed at the first surface 211 of the first lens 21 by a coating method, and the coating method may make the film layer of the light splitting element 40 more firm. The beam splitting element 40 is used for splitting light so that a part of the light 11 is transmitted and another part of the light 11 is reflected, for example, a transflective film. It is also possible to let light 11 in one state be transmitted and light 11 in another state be reflected, for example a polarizing reflective film 31b, the polarizing reflective film 31b having a transmission axis, when the polarization state of light 11 is in the same direction as the transmission axis, light 11 is transmitted, and when the polarization state of light 11 is in the different direction from the transmission axis, light 11 is absorbed or reflected. The material of the plate element 30 may be pmma (polymethyl methacrylate) or glass or other optical materials. The quarter-wave plate 31a and the polarization reflection film 31b may also be adhesively fixed to the fifth surface 31 of the flat plate member 30, so that the installation process is convenient and fast. The second lens 22 can be MFD80 low abbe number glass, or other glass or optical material for correcting chromatic aberration; the material package of the first lens 21 may be coc (cyclic Olefin copolymer) cyclic Olefin copolymer material, or may be other types, such as glass, cop (cyclic Olefin polymer) cyclic Olefin polymer material, pmma (polymethyl methacrylate) polymethyl methacrylate, and the like, and it is sufficient to ensure that the abbe number of the first lens 21 is different from that of the second lens 22.

In addition, the shape of the first lens 21 can be a biconvex type configuration in which two opposite surfaces are both convexly disposed, and the second lens 22 can be a biconcave type configuration in which two opposite surfaces are both concavely disposed corresponding to the shape of the first lens 21, so that the second surface 212 can be embedded and attached in the third surface 221, thereby reducing an air gap between the second surface 212 and the third surface 221, which not only can reduce the volume of the cemented lens 20, so as to further reduce the total optical length of the optical module, but also can reduce the passing air when the light 11 passes through the cemented lens 20, thereby reducing ghost and stray light formed by passing through different refractive index media. Of course, the first lens 21 may also be a plano-convex type arrangement in which one side surface is a plane and the other side surface is a convex surface, and then the second lens 22 is a plano-concave type arrangement in which one side surface is a plane and the other side surface is a concave surface, or both the first lens 21 and the second lens 22 are meniscus type arrangements, which can be selected by those skilled in the art according to specific situations.

In the technical solution of the present invention, the display 10 emits light 11, and the emitted light 11 is circularly polarized light. When the light rays 11 are emitted to the cemented lens 20, the light rays 11 first pass through the light splitting element 40 on the first surface 211 of the first lens 21, one light ray 11 is transmitted through the light splitting element 40, and the other light ray 11 is reflected. The light 11 transmitted through the light splitting element 40 is sequentially emitted to the second surface 212 of the first lens 21 and the third surface 221 and the fourth surface 222 of the second lens 22, and then the light 11 transmitted through the fourth surface 222 is emitted to the quarter-wave plate 31a of the fifth surface 31 of the flat plate element 30, at which time the polarization state of the circularly polarized light 11 is changed, the circularly polarized light is converted into linearly polarized light, the linearly polarized light 11 is emitted to the polarization reflection film 31b again, at which time, the linearly polarized light is reflected in a direction different from the transmission direction of the polarization reflection film 31b, and the reflected light 11 passes through the quarter wave plate 31a again, so that the linearly polarized light is changed into circularly polarized light again and reflected to pass through the second lens 22 and the first lens 21 in order, when the light ray 11 is reflected again through the light splitting element 40, part of the light ray 11 will be reflected again and will pass through the first lens 21 and the second lens 22 of the cemented lens 20 in sequence. At this time, the light 11 is circularly polarized light, after reflection, the rotation direction of the light 11 is changed, and when the light 11 passes through the quarter-wave plate 31a again, it is converted into linearly polarized light again, at this time, the polarization direction of the linearly polarized light is the same as the transmission direction of the polarization reflection film 31b, and the light 11 passes through the flat plate element 30, and forms an image at the position of the human eye 50. It can be seen that the light 11 is folded back at the flat plate element 30 and the cemented lens 20, and the light 11 is continuously amplified and transmitted in the whole process. The image magnifying and transmitting device has the advantages that the image magnifying and transmitting is achieved in a limited space, the optical total length is favorably reduced, a user can conveniently wear the device, the Abbe number of the material of the first lens 21 made of different materials and the second lens 22 are adopted, different refractive indexes and Abbe numbers are selected to be matched, accordingly, the light 11 is compensated to eliminate chromatic aberration when being refracted through the first lens 21 and the second lens 22, the optical total length of an optical system can be reduced, the effect of low chromatic aberration is achieved, the compensation pressure of later-stage imaging software on display pixels of the image is reduced, the imaging quality is improved, and imaging is clearer. In addition, the quarter-wave plate 31a and the polarization reflection film 31b are arranged on the fifth surface of the flat panel element 30, so that the quarter-wave plate 31a and the polarization reflection film 31b are positioned on the inner side of the flat panel element 30 close to the display 10, external scratches are prevented, reliability is improved, installation difficulty can be reduced, the quarter-wave plate 31a and the polarization reflection film 31b can be independently installed, and installation efficiency is improved.

In the above embodiment, during the propagation of the light 11, an included angle may be formed between the vibration direction of the partially linearly polarized light and the transmission direction of the polarization reflection film 31b, and the included angle ranges from 0 ° to 90 °, that is, the vibration direction of the partially linearly polarized light is neither the same as nor perpendicular to the transmission direction of the polarization reflection film 31 b. Thus, after the light 11 passes through the polarization reflection film 31b, stray light occurs, and in order to reduce the stray light, the optical module further includes a polarization film 31c, and the polarization film 31c is disposed on a side of the polarization reflection film 31b away from the quarter-wave plate 31 a. The polarizing film 31c has a transmission direction, and the transmission direction of the polarizing film 31c is the same as the transmission direction of the polarizing reflective film 31 b. The polarizing film 31c filters the passing light 11, and the light 11 different from the transmission direction is filtered and absorbed, so that the light 11 passing through the optical module can keep the consistent vibration direction, and the occurrence of stray light is reduced.

In an embodiment of the present disclosure, in order to increase the transmittance of the light 11, the optical module further includes a first antireflection film 31d, and the first antireflection film 31d is disposed on a side of the quarter-wave plate 31a away from the polarization reflection film 31 b. The first antireflection film 31d increases the number of the passing light rays 11, and reduces the reflection and absorption of the cemented lens 20 on the light rays 11. In addition, the first antireflection film 31d may be provided by pasting or plating, which is simple to operate. Of course, an antireflection film may be disposed on the fourth surface 222, and the antireflection film may be disposed according to specific situations by those skilled in the art.

Further, the first antireflection film 31d, the quarter-wave plate 31a, the polarization reflection film 31b and the polarization film 31c are all film layer structures, and the first antireflection film 31d, the quarter-wave plate 31a, the polarization reflection film 31b and the polarization film 31c are combined into an integral film layer. Wherein, through an integral rete structure, can compress rete thickness, reduce the optical cement layer between every rete. Meanwhile, the installation of three film layers can be completed by pasting one integral film layer.

In an embodiment of the present application, the plate element 30 further has a sixth surface 32 facing away from the second lens 22, and the sixth surface 32 is attached with a second antireflection film 32 a. In order to supplement the quantity of the light rays 11 passing through the flat panel element 30, a second antireflection film 32a is also disposed on the sixth surface 32, so as to increase the quantity of the imaging light rays 11 irradiated to the human eye 50 and improve the imaging quality. In addition, in order to improve the reliability of the optical module, a layer of hardened protective film 32b is disposed on a side close to human eye 50, that is, a side of second antireflection film 32a away from sixth surface 32, so as to prevent end user from scratching and improve the reliability of the optical module.

Further, the fifth surface 31 and the sixth surface 32 of the flat plate member 30 are both flat; wherein, in order to further facilitate the operator to carry out the film layer on the fifth surface 31 and the sixth surface 32 of the flat plate element 30 or plate, so that the fifth surface 31 and the sixth surface 32 can be arranged in a plane, thereby ensuring the accuracy and efficiency of the film pasting, and simultaneously, the processing of the plane is easier, which is beneficial to reducing the cost.

In an embodiment of the present application, the thickness value of the plate member 30 is T1, the thickness value of the first lens 21 is T2, the thickness value of the second lens 22 is T2, and the distance between the second surface 212 and the third surface 221 is L, then: l is more than or equal to 1mm and less than or equal to 2mm, and T1 is more than or equal to 0.5mm and less than or equal to 1.5 mm; t2 is more than or equal to 3mm and less than or equal to 5mm, and T3 is more than or equal to 3mm and less than or equal to 5.5 mm. Where L is a distance between the second surface 212 and the third surface 221, if L is less than 1mm, the difficulty of installation is large, and if L is greater than 2mm, the air gap between the second surface 212 and the third surface 221 is too large, and the imaging quality may be degraded. If T1 is less than 0.5mm, the plate element 30 is too thin, and it is not easy to attach the quarter-wave plate 31a and the polarization reflection film 31b to the plate element 30, and if T1 is greater than 1.5mm, the plate element 30 is too thick, which increases the volume of the entire optical module. Similarly, the oversize of T2 and T3 also increases the volume of the whole optical module, and the undersize or the oversize of T2 and T3 both reduce the imaging quality, so that the thickness value T2 of the first lens 21 should be 3mm to 5mm, and the thickness value T3 of the second lens 22 should be 3mm to 5.5 mm.

In an embodiment of the present application, the radius value of the first surface 211 is R1, the conic coefficient of the first surface 211 is C1, the radius value of the second surface 212 is R2, the conic coefficient of the second surface 212 is C2, the radius value of the third surface 221 is R3, the conic coefficient of the third surface 221 is C3, and the radius value of the fourth surface 222 is R4, which satisfy: r4 is more than or equal to 150mm and less than or equal to 190mm, and R2 is more than or equal to 150mm and less than or equal to R3 and less than or equal to 200 mm; the parameters are flexibly selected in the corresponding range, so that the imaging quality is ensured. If the parameters are selected outside the corresponding ranges, the imaging quality is easily degraded.

In an embodiment of the present application, a distortion of the optical module is less than 19.4%, a chromatic aberration of the optical module is less than 12 μm, a field curvature of the optical module is less than 0.5mm, and a spot diameter of the optical module is less than 38.8 μm. The parameters are flexibly selected in the corresponding range, so that the imaging quality is ensured. If the parameters are selected outside the corresponding ranges, the imaging quality is easily degraded.

Referring to fig. 4-6, when the first lens element 21 is a biconvex structure, the second lens element 22 is a meniscus structure, and the first lens element 21 and the second lens element 22 are made of a combination of low-stress glass and plastic, the imaging spot is smaller than 38.8 um. The field curvature is less than 0.2mm, and the distortion of the maximum field position is less than 5%. The maximum dispersion value is less than 12um, and the optical module meets the design requirements through the parameters, can meet the requirements of terminal users in the later period by matching with later-period software correction, and when the maximum dispersion value is 450nm to 540nm, the LCA (vertical color aberration) is-6 nm; when the wavelength is in the 540-610 nm band, LCA is 6 nm; the whole RGB is 450 nm-610 nm; LCA is 12 nm.

The invention also provides a head-mounted display device, which comprises a shell and the optical module, wherein the optical module is arranged on the shell, the total optical length of the optical module in the horizontal direction is TTL1, and the total optical length of the optical module in the vertical direction is TTL2, so that the requirements are met: TTL1 is less than 12mm, TTL2 is less than 29 mm. For example, TTL 1-11.8 mm and TTL 2-28.2 mm. Based on the design of above-mentioned optical module, optical module's focal length can be 14.3m, and the size of the light emitting area of display 10 is in 0.85 ~ 1.05 inches, and the formation of image angle of vision is 70, and in this angular range, the user can observe clear formation of image.

The design results of one embodiment are shown in the first and second tables, which respectively include the number (Surface) of the optical Surface numbered in order from the human eye (STOP) to the display screen, the curvature (C) of each optical Surface on the optical axis, and the distance (T) from the human eye (STOP) to the next optical Surface on the optical axis of the display screen. And even-order aspherical surface coefficients α 2, α 3, α 4, wherein the aspherical surface coefficients may satisfy the following equations.

Wherein z is a coordinate along the optical axis direction, Y is a radial coordinate in units of lens length, C is a curvature (1/R), k is a conic Coefficient (cone Constant), α i is a Coefficient of each high-order term, 2i is a high power of aspheric surface (the order of aspheric Coefficient), and the patent design considers the smoothness of field curvature and the spherical Coefficient without high-order term to 4 orders.

Watch 1

Watch two

It should be noted that the thickness in table one refers to the distance from the optical surface to the next optical surface, positive values of the thickness refer to the distance from the display 10 to the human eye 70, and negative values of the thickness refer to the distance from the human eye 70 to the display 10. The term "material" means that the material is present from one optical surface to the next, and the meaning of MIRROR (reflection) is not material, but means that the optical surface has a reflection effect. The data represented by 4th in table two is a 4-order coefficient for substituting into the corresponding face-type calculation formula, and the data represented by 6th is a 6-order coefficient for substituting into the corresponding face-type calculation formula.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An optical module, comprising:

a display that emits light for imaging display;

the cemented lens is arranged in the light outgoing direction of the display and comprises a first lens and a second lens which are sequentially arranged along the direction deviating from the display, the first lens is provided with a first surface facing the display and a second surface facing away from the display, the second lens is provided with a third surface facing the display and a fourth surface facing away from the display, the second surface and the third surface are arranged in a cemented manner, the direction of the second surface deviating from the display is convex, the direction of the third surface facing the display is concave, and the Abbe number of the material of the first lens is different from the Abbe number of the material of the second lens;

the light splitting element is arranged on the first surface; and

2. The optical module of claim 1 further comprising a polarizing film disposed on a side of the polarizing reflective film facing away from the quarter wave plate.

3. The optical module of claim 2, further comprising a first anti-reflection film disposed on a side of the quarter-wave plate facing away from the polarizing reflective film.

4. The optical module of claim 3, wherein the first antireflection film, the quarter-wave plate, the polarizing reflective film and the polarizing film are all film layer structures, and the first antireflection film, the quarter-wave plate, the polarizing reflective film and the polarizing film are integrated into a single film layer.

5. The optical module of claim 1, wherein the plate element further comprises a sixth surface facing away from the second lens, and a second anti-reflection film is attached to the sixth surface.

6. The optical module of claim 5 wherein the fifth surface and the sixth surface of the plate member are both planar.

7. The optical module of any one of claims 1 to 6, wherein the thickness value of the plate element is T1, the thickness value of the first lens is T2, the thickness value of the second lens is T2, and the distance between the second surface and the third surface is L, then:

0.5mm≤T1≤1.5mm，3mm≤T2≤5mm；

3mm≤T3≤5.5mm，1mm≤L≤2mm。

8. an optical module according to any one of claims 1 to 6, wherein the radius of the first surface is R1, the cone coefficient of the first surface is C1, the radius of the second surface is R2, the cone coefficient of the second surface is C2, the radius of the third surface is R3, the cone coefficient of the third surface is C3, and the radius of the fourth surface is R4, such that:

35mm≤R1≤60mm，150mm≤R2＝R3≤200mm；

C1＝C2＝C3≤20，150mm≤R4≤190mm。

9. the optical module of any of claims 1-6 having a distortion of less than 19.4%, a chromatic aberration of less than 12 μm, a field curvature of less than 0.5mm, and a spot diameter of less than 38.8 μm.

10. A head-mounted display device, wherein the head-mounted display device comprises a housing and the optical module according to any one of claims 1 to 9, the optical module is disposed on the housing, and the total optical length of the optical module in the horizontal direction is TTL1, and the total optical length of the optical module in the vertical direction is TTL2, then:

TTL1＜12mm，TTL2＜29mm。