CN115933188A - Optical module and head-mounted display equipment - Google Patents

Abstract

The embodiment of the application provides an optical module and head-mounted display equipment. The optical module includes: a lens group comprising at least one lens; the optical module further comprises a polarizing element, a light splitting element and a phase retarder, wherein the polarizing element, the light splitting element and the phase retarder are arranged on any side of a lens in the lens group; the effective caliber B2 of the light splitting element is 45-65 mm; the distance from the polarizing element to the light splitting element is A2; the curvature radius of the light splitting element is C6; wherein, the optical module satisfies: 0.1 < A2/(C6/2) < 0.5.

Description

Optical modules and head-mounted display devices

technical field

The embodiments of the present application relate to the technical field of near-eye display imaging, and more specifically, the embodiments of the present application relate to an optical module and a head-mounted display device.

Background technique

In recent years, augmented reality (Augmented Reality, AR) technology and virtual reality (Virtual Reality, VR) technology have been applied in, for example, smart wearable devices and developed rapidly. The core components of augmented reality technology and virtual reality technology are optical modules. The quality of the image displayed by the optical module will directly determine the quality of the smart wearable device.

Among them, in the pancake optical system design scheme, the distance between the polarizing element and the light splitting element determines the distance that the optical path can be folded, and determines the extent to which the total length of the system can be reduced. If the aperture is too large, it will adversely affect the overall miniaturization and compact design of the pancake optical system. Therefore, how to make the distance between the polarizing element and the beam splitting element better match the entire focal length of the pancake optical system to solve the overall miniaturization and compact design of the pancake optical system is a technical problem that needs to be solved at present.

Contents of the invention

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

In a first aspect, the present application provides an optical module, the optical module comprising:

a lens group comprising at least one lens;

The optical module also includes a polarizing element, a light splitting element, and a phase retarder, and any side of the lens in the lens group is provided with the polarizing element, the light splitting element, and a phase retarder;

The effective aperture B2 of the light splitting element is 45mm-65mm;

The distance from the polarizing element to the light splitting element is A2; the radius of curvature of the light splitting element is C6;

Wherein, the optical module satisfies: 0.1<A2/(C6/2)<0.5.

Optionally, the distance A2 from the polarizing element to the light splitting element is 8mm-17mm.

Optionally, the focal length range of the optical module is 15mm-35mm.

Optionally, the lens group includes a first lens close to the human eye side, the first lens has a first surface facing the human eye side, and the first lens has a second surface facing the display screen side;

The polarizing element is disposed on one side of the first surface, or the polarizing element is disposed on one side of the second surface.

Optionally, the lens group includes a lens near the display screen, and the light splitting element is arranged on the side of the lens near the display screen.

Optionally, the phase delayer includes a first phase delayer;

The lens group includes a first lens close to the human eye side, the first lens has a first surface facing the human eye side, and the first lens has a second surface facing the display screen side;

The first phase retarder is disposed on one side of the first surface, or the first phase retarder is disposed on one side of the second surface, wherein the first phase retarder is relatively opposite to the The polarizing element is arranged closer to the side of the display screen.

Optionally, the phase delayer includes a second phase delayer;

The lens group includes a lens close to the display screen, and the second phase retarder is arranged on the side of the lens close to the display screen.

Optionally, the optical module further includes a display screen, and the size of the display screen is D1;

The distance from the polarizing element to the display screen is L1;

The effective aperture of the polarizing element is B1;

Wherein the optical module satisfies: 0<(B1/2-D1/2)/L1<0.8.

Optionally, the distance L1 from the polarizing element to the display screen is 12mm-25mm.

In a second aspect, a head-mounted display device is provided. The head-mounted display device includes:

casing; and

The optical module as described in the first aspect.

According to the embodiment of the present application, by controlling the ratio of the distance from the polarizing element to the light splitting element to half of the radius of curvature of the light splitting element, the optical module has better compactness and the overall volume of the optical module is reduced.

Other features of the present specification and advantages thereof will become apparent through the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the embodiments of the specification and together with the description serve to explain the principles of the specification.

FIG. 1 is a first structural schematic diagram of an optical module provided by an embodiment of the present application.

FIG. 2 shows the second structural schematic diagram of the optical module provided by the embodiment of the present application.

FIG. 3 is a schematic diagram of the third structure of the optical module provided by the embodiment of the present application.

Explanation of reference signs:

1. Display screen; 2. Lens group; 21. First lens; 22. Second lens; 23. Third lens; 3. Polarization element; 4. Diaphragm; 5. Spectroscopic element; 6. First phase retarder .

Detailed ways

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

The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as any limitation of the application, its application or uses.

Techniques and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques and devices should be considered part of the description.

In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other instances of the exemplary embodiment may have different values.

It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

Among them, in the design scheme of the pancake optical system, the design scheme of the pancake optical system is to use the modulation effect of the polarization element on the polarized light to realize the limited transmission or reflection of the light of a specific polarization state, so as to realize the folding of the optical path. Among them, in the pancake optical system design scheme, the distance between the polarizing element and the light splitting element determines the distance that the optical path can be folded, and determines the extent to which the total length of the system can be reduced. If the aperture is too large, it will adversely affect the overall miniaturization and compact design of the pancake optical system. Therefore, how to make the distance between the polarizing element and the beam splitting element better match the entire focal length of the pancake optical system to solve the overall miniaturization and compact design of the pancake optical system is a technical problem that needs to be solved at present.

Based on the above technical problems, the first aspect of the embodiment of the present application provides an optical module, the optical module is a folded optical path optical structure design, which can include at least one optical lens, and can be applied to head-mounted display devices ( head mounted display (HMD), for example, a VR head-mounted device, such as VR glasses or a VR helmet, etc., which are not specifically limited in this embodiment of the present application.

The optical module and the head-mounted display device provided by the embodiment of the present application will be described in detail below with reference to FIGS. 1 to 3 .

An embodiment of the present application provides an optical module. As shown in FIGS. 1 to 3 , the optical module includes: a lens group 2 , and the lens group 2 includes at least one lens. The optical module also includes a polarizing element 3 , a light splitting element 5 and a phase retarder, and the polarizing element 3 , the light splitting element 5 and a phase retarder are arranged on either side of the lens in the lens group 2 .

The effective aperture B2 of the light splitting element 5 is 30mm-65mm.

The distance between the polarizing element 3 and the light splitting element 5 is A2; the radius of curvature of the light splitting element 5 is C6. Wherein, the optical module satisfies: 0.1<A2/(C6/2)<0.5.

In other words, the optical module mainly includes a lens group 2, a polarizing element 3, a light splitting element 5 and a phase retarder.

The function of the lens group 2 is to enlarge and analyze light. For example, in display devices such as VR (Virtual Reality, virtual reality), in order to ensure that the user obtains an enlarged display image, the light needs to be enlarged, and the lens group 2 is used to ensure that the user obtains a recognizable enlarged image. In the folded optical path, considering that the light has been folded, compared with the direct optical architecture, the number of lenses in the optical architecture of the folded optical path can be at most three.

Specifically, in order to realize the configuration of the folded optical path, a polarizing element 3 , a light splitting element 5 and a phase retarder are arranged on either side of the lens in the lens group 2 . For example, a light splitting element 5 is arranged on the side of the lens group 2 towards the display screen 1; a polarizing element 3 is arranged on the side of the lens group 2 facing away from the display screen 1, or a polarizing element 3 is arranged on one side of a lens in the lens group 2 ; Set a phase retarder on the side of the lens group 2 facing the display screen 1, or set a phase retarder on one side of a lens in the lens group.

Wherein the polarizing element 3 can be used to reflect the S polarized light through the P polarized light; or, the polarized reflection element can be used to reflect the P polarized light through the S polarized light. Specifically, the polarizing element 3 has a polarization transmission direction, and the light can pass through the polarization element 3 smoothly only when the light vibrates along the polarization transmission direction, and the light vibrating in other directions is reflected when encountering the polarization element 3 . For example, the polarizing element 3 may be a polarized reflective film, or a reflective polarizer. In this embodiment, no matter where the polarizing element 3 is located, the distance between the polarizing element 3 and the light splitting element 5 is defined as A2.

The phase retarder can be used to change the polarization state of light in the folded optical path structure. For example, it is possible to convert linearly polarized light into circularly polarized light, or convert circularly polarized light into linearly polarized light. For example the phase retarder may be a quarter wave plate.

When the light passes through the light splitting element 5 , part of the light is transmitted and the other part is reflected, and the absorption of the light is not considered. For example, the light propagating from the display screen 1 to the human eye side can pass through the light splitting element 5 , while the light propagating from the human eye side to the display screen 1 is reflected on the light splitting element 5 . The light splitting element 5 may be a semi-reflective film or a polarizing film. In this embodiment, no matter where the polarizing element 3 is arranged, the distance between the polarizing element 3 and the light splitting element 5 is defined as A2, and the radius of curvature of the light splitting element 5 is defined as C6.

In this embodiment, A2/(C6/2) is limited within this range, that is, 0.2<2A2/C6<1 is defined, and at the same time, the effective aperture B2 of the light splitting element 5 is limited so that the structure of the optical module has compactness. Wherein the effective aperture B2 of the light-splitting element 5 can be: the light-splitting element 5 is arranged on the surface of the lens, wherein the effective aperture B2 of the light-splitting element 5 can be the effective aperture B2 of the lens provided with the light-splitting element 5; or the light-splitting element is arranged on the optical component ( The optical component is located between adjacent lenses, or the optical component is located between the lens and the display screen 1 ), wherein the effective aperture B2 of the light splitting element 5 can be the effective aperture B2 of the optical component provided with the light splitting element 5 .

Specifically, the embodiment of the present application does not specifically limit the specific installation positions of the polarizing element 3 and the light-splitting element 5, but only limits the distance between the polarizing element 3 and the light-splitting element 5 as A2, that is, defines the distance between the polarizing element 3 and the light-splitting element 5 on the optical axis The distance above is A2. The light is folded between the polarizing element 3 and the light splitting element 5, and the distance A2 between the polarizing element 3 and the light splitting element 5 is an important factor to reduce the total length of the optical module system, which can reduce the light by 2*A2 compared with the straight-through optical path length.

The longer the folded light path of the light from the polarizing element 3 to the light splitting element 5 is, the longer the distance from the polarizing element 3 to the light splitting element 5 is, and the smaller the overall optical length of the optical module is, but the focal length of the optical module can be maintained at within a certain range. Therefore, in this embodiment, the ratio relationship of A2/(C6/2) is limited, so that the distance from the polarizing element 3 to the light splitting element 5 can be reasonably matched with the system focal length of the optical module.

Wherein the system focal length of the optical module reflects on the optical power of the optical module (the reciprocal of the system focal length of the optical module is the overall optical power of the optical module), in the pancake optical system design scheme (i.e. the application's In the optical module), the focal power of the entire system is mainly contributed by the radius of curvature of the lens provided with the spectroscopic element 5, that is, the focal power of the lens provided with the spectroscopic element 5 is relatively large. Therefore, this embodiment limits the ratio of A2/(C6/2), so that the distance from the polarizing element 3 to the light splitting element 5 can be reasonably matched with the system focal length of the optical module, making the overall compactness of the optical module more compact. good.

Among them, the focal power of the whole system mainly comes from the radius of curvature of the lens provided with the spectroscopic element 5, mainly because the spectroscopic element 5 reflects the light, and the deflection effect on the peripheral field of view and the deflection effect on the central field of view Larger, the optical power contributed by the surface or lens where the polarizing element 3 is located is smaller, and the polarization effect of light on the peripheral field of view on the lens or surface where the polarizing element 3 is disposed is small. Therefore, the focal power of the whole system mainly comes from the radius of curvature of the lens provided with the light splitting element 5 , rather than from the radius of curvature of the lens provided with the polarizing element 3 . Therefore, the radius of curvature of the lens provided with the light splitting element 5 affects the overall focal length of the optical module.

In addition, considering that the distance A2 between the light-splitting element 5 and the polarizing element 3 is longer, the aperture B2 of the lens where the light-splitting element 5 is located is larger, and the larger the aperture B2 of the lens where the light-splitting element 5 is located, will expand the aperture of the optical module system. Miniaturization of the system can have negative effects.

Therefore in summary, considering the focal length of the optical module, the radius of curvature of the light-splitting element 5, and the interrelationship between the distance from the polarizing element 3 to the light-splitting element 5, and considering the distance from the polarizing element 3 to the light-splitting element 5, and the light-splitting The relationship between the effective aperture B2 of the element 5, the embodiment of the present application limits the ratio of A2/(C6/2) to 0.1<A2/(C6/2)<0.5, and at the same time limits the The effective diameter B2 of the lens is 45mm-65mm, so that the structure of the optical module is compact.

It should be noted that, in the embodiments of the present application, those skilled in the art can flexibly adjust the distance from the polarizing element 3 to the light splitting element 5 in the optical module according to specific needs, and the ratio relationship between the radius of curvature of the light splitting element 5, as long as the The ratio relationship can be controlled within a preset range.

For example, A2/(C6/2) may range from 0.2 to 0.4.

For another example, the range of A2/(C6/2) may be 0.25˜0.35.

For another example, the range of A2/(C6/2) may be 0.15˜0.45.

Within the ranges of the above ratios, a compact optical module system can be realized.

Certainly, in the embodiment of the present application, the ratio relationship between the distance from the polarizing element 3 to the light splitting element 5 in the optical module and the radius of curvature of the light splitting element 5 is not limited to the above three examples, and those skilled in the art can base on Flexible adjustment is required, which is not specifically limited in this embodiment of the present application.

In an optional embodiment, the lens group 2 includes at least two lenses.

In this embodiment, when the lens group 2 only includes one lens, when the optical module magnifies the light through only one lens, it is necessary to increase the distance between one lens and the display screen 1, so as to ensure the display All the incident light emitted by the screen 1 is received by a lens, and the parameters of the lens need to be specifically limited to ensure that a lens can magnify the light. Therefore, when the lens group 2 only includes one lens, the compactness of the optical module will be the worst. Therefore, in this embodiment, regardless of the fact that the optical module includes only one lens, this embodiment defines that the lens group 2 includes at least two lenses.

In one embodiment, the distance between the polarizing element 3 and the light splitting element 5 is 8mm-17mm.

In this embodiment, the distance from the polarizing element 3 to the light splitting element 5 is limited, that is, the length of the folded optical path in the optical module is limited. This embodiment limits the length of the folded optical path, and the length of the folded optical path contributes more to shortening the total optical length of the system. Compared with the direct optical path, the folded optical path of this application reduces the optical path by 12mm-34mm, which can make The overall optical length of the optical module is reduced. For example, the distance A2 from the polarizing element 3 to the light splitting element 5 can be 8mm-15mm, or the distance A2 from the polarizing element 3 to the light splitting element 5 can be 10mm-16.5mm, or the distance A2 from the polarizing element 3 to the light splitting element 5 can be 13mm- 16mm.

In addition, in this embodiment, the distance from the polarizing element 3 to the light-splitting element 5 is limited so that the distance A2 from the polarizing element 3 to the light-splitting element 5 is limited to the ratio of the half radius of curvature of the light-splitting element 5 within this range , so as to achieve the purpose of reducing the volume of the optical module and improving the compactness of the optical module.

In addition, this embodiment limits the distance A2 from the polarizing element 3 to the light splitting element 5, combined with the effective aperture B2 of the light splitting element 5, so that the distance A2 from the polarizing element 3 to the light splitting element 5 is reasonably matched with the effective aperture of the light splitting element 5 For example, by limiting the effective aperture B2 of the lens where the light-splitting element 5 is located, and the ratio of the distance A2 from the polarizing element 3 to the light-splitting element 5, the ratio of B2/A3 can be 4-6, so that the compactness of the optical module and the optical module The effective aperture of the optical module is matched, the optical module has compact performance, and the overall effective aperture of the optical module is not too large, and the optical module meets the requirements of lightness and miniaturization.

In this embodiment, the distance between the polarizing element 3 and the light-splitting element 5 is 8mm-17mm, and the radius of curvature of one-half of the corresponding light-splitting element 5 is greater than 16mm and less than 170mm, that is, the radius of curvature C6 of the light-splitting element 5 is greater than 32mm and Less than 340mm.

In one embodiment, the focal length range of the optical module is 15mm-35mm.

In this embodiment, the focal length of the optical module is limited, that is, the overall optical power of the optical module is limited. For example, the focal length range of the optical module is 15mm-35mm, and the overall focal power of the optical module is 1/35-1/15.

This embodiment limits the focal length of the optical module. The shorter the system focal length of the optical module is, the smaller the overall optical length of the entire optical module is, and the greater the contribution of the folded optical path is to shortening the total optical length of the optical module. , enabling the optical module to achieve better system compactness.

In an optional embodiment, the radius of curvature C6 of the light splitting element 5 is: 50mm-145mm.

In this embodiment, the radius of curvature of the light-splitting element 5 is defined, that is, the radius of curvature of the surface on which the light-splitting element 5 is located is defined, and the radius of curvature of the surface on which the light-splitting element 5 is located is positive, that is, it can basically reflect the optical module. The optical power of the entire system (that is, the main contribution of the optical power of the entire system comes from the radius of curvature of the surface where the light splitting element 5 is located), the optical power of the entire system of the optical module is positive. For example, the surface of the lens where the light-splitting element 5 is located can be convex, which can better correct the light in the field of view.

In addition, in this embodiment, the radius of curvature of the surface where the light-splitting element 5 is located is defined so that the ratio of the distance A2 from the polarizing element 3 to the light-splitting element 5 to the half of the radius of curvature of the surface where the light-splitting element 5 is located is defined here In order to achieve the purpose of reducing the volume of the optical module and improving the compactness of the optical module.

In one embodiment, the lens group 2 includes a first lens 21 close to the human eye side, the first lens 21 has a first surface facing the human eye side, and the first lens 21 has a surface facing the display screen side. the second surface of

The polarizing element 3 is arranged on one side of the first surface, or the polarizing element 3 is arranged on one side of the second surface.

In this embodiment, regardless of whether the lens group includes one lens, two lenses, or three lenses, etc., the lens group 2 includes the first lens 21 close to the human eye side, that is, the lens group 2 includes the first lens 21 that is close to the human eye. The first lens 21 disposed adjacent to the eyes processes the light through the first lens 21 , so that the processed light is output to the human eye for imaging.

1 and 2, the first lens 21 includes a first surface facing the human eye, wherein a polarizing element 3 is arranged on one side of the first surface, for example, a polarizing element 3 may be arranged on the first surface, Alternatively, a polarizing element 3 is arranged between the human eye and the first surface, wherein the polarizing element 3 can be arranged between the human eye and the first surface by means of optical components.

Referring to Fig. 3, the first lens 21 includes a second surface facing away from the human eye, wherein a polarizing element 3 is arranged on one side of the second surface, for example, a polarizing element 3 may be arranged on the second surface, or on the second surface A polarizing element 3 is arranged between a lens 21 and a lens adjacent to the first lens 21 , for example, the polarizing element 3 may be arranged between two adjacent lenses by means of optical components.

In this embodiment, the specific location of the polarizing element 3 is not particularly limited, as long as the ratio between the distance from the polarizing element to the light splitting element and the half radius of curvature of the light splitting element is limited to the above range.

In one embodiment, as shown in FIGS. 1-3 , the lens group 2 includes a lens near the display screen, and the light splitting element 5 is arranged on the side of the lens near the display screen.

In this embodiment, regardless of whether the lens group 2 includes one lens, two lenses or three lenses, etc., the lens group 2 includes a lens close to the display screen 1, that is, the lens group includes lenses that are close to the display screen 1. The light emitted from the display screen 1 will be transmitted through the lens first, and then the light will be returned and finally transmitted to the human eye.

In this embodiment, the light splitting element 5 is arranged on the side of the lens close to the display screen, near the display screen. For example, the lens close to the display screen includes a surface facing the display screen, on which a light splitting element 5 is arranged, or a light splitting element 5 is set between the surface and the display screen 1, for example, the light splitting element 5 can be arranged on the surface by means of optical components Between the surface and the display screen 1.

In this embodiment, the specific location of the light splitting element 5 is not particularly limited, as long as the ratio between the distance from the polarizing element to the light splitting element and the half radius of curvature of the light splitting element is limited to the above range.

In one embodiment, the phase retarder includes a first phase retarder 6; the lens group 2 includes a first lens 21 close to the human eye side, and the first lens 21 has a first surface facing the human eye side , and the first lens 21 has a second surface facing the display screen side; the first phase retarder 6 is provided on one side of the first surface, or a The first phase retarder 6, wherein the first phase retarder 6 is arranged closer to the side of the display screen than the polarizing element.

In this embodiment, regardless of whether the lens group 2 includes one lens, two lenses, or three lenses, etc., the lens group 2 includes the first lens 21 close to the human eye side, that is, the lens group 2 includes the same The first lens 21 disposed adjacent to the human eye processes the light through the first lens 21 so that the processed light is output to the human eye for imaging.

1 and 2, the first lens 21 includes a first surface facing the human eye, wherein a first phase retarder 6 is arranged on one side of the first surface, for example, a second phase retarder 6 may be arranged on the first surface. A phase retarder 6, or a first phase retarder 6 is arranged between the human eye and the first surface, wherein the first phase retarder 6 can be arranged between the human eye and the first surface by means of optical components.

Referring to Fig. 3, the first lens 21 includes a second surface facing away from the human eye, wherein a first phase retarder 6 is arranged on one side of the second surface, for example, a first phase retardation can be arranged on the second surface device 6, or a first phase retarder 6 is set between the first lens 21 and the lens adjacent to the first lens 21, for example, the first phase retarder 6 can be arranged on two adjacently arranged lenses by means of optical components between lenses.

In this embodiment, the first phase retarder 6 is arranged closer to the display screen 1 relative to the polarizing element, for example, the polarizing element 3 and the first phase retarder 6 are arranged on the first surface of the first lens 21, wherein the first A phase retarder 6 is arranged closer to the first lens 21 relative to the polarizing element 3; or the polarizing element 3 and the first phase retarder 6 are arranged on the second surface of the first lens 21, wherein the first phase retarder 6 is relatively The polarizing element 3 is arranged farther away from the first lens 21 , specifically, so that the first phase retarder 6 is arranged closer to the display screen 1 relative to the polarizing element. Specifically, the polarization state of the light passing through the first phase retarder 6 changes, wherein the light passing through the first phase retarder 6 for the first time is reflected by the polarizing element 3, and the reflected light is processed by the spectroscopic element 5, and again After passing through the first phase retarder 6 , the light passing through the first phase retarder 6 for the second time is transmitted by the polarizing element 3 and transmitted to human eyes.

In one embodiment, the phase retarder includes a second phase retarder; the lens group 2 includes a lens near the display screen, and the second phase retarder is arranged on the side of the lens near the display screen.

In this embodiment, regardless of whether the lens group 2 includes one lens, two lenses or three lenses, etc., the lens group 2 includes a lens close to the display screen 1, that is, the lens group includes lenses that are close to the display screen 1. The light emitted from the display screen 1 will be transmitted through the lens first, and then the light will be returned and finally transmitted to the human eye.

In this embodiment, the light splitting element 5 is arranged on the side of the lens close to the display screen, near the display screen. For example, the lens close to the display screen includes a surface facing the display screen, on which a second phase retarder is arranged, or a second phase retarder is arranged between the surface and the display screen 1, for example, the second phase retarder can It is arranged between this surface and the display screen 1 by means of optical components. Wherein the second phase retarder is arranged closer to the display screen 1 than the light splitting element 5 . Specifically, the light splitting element 5 and the second phase retarder are arranged on the surface of the lens close to the display screen 1 facing the display screen 1 , wherein the second phase retarder is arranged closer to the display screen 1 than the light splitting element 5 .

In one embodiment, as shown in FIGS. 1-3 , the optical module further includes a display screen 1 , and the size of the display screen 1 is D1. The distance between the polarizing element 3 and the display screen 1 is L1.

The effective aperture of the polarizing element 3 is B1. Wherein the optical module satisfies: 0<(B1/2-D1/2)/L1<0.8.

In this embodiment, the optical module also includes a display screen 1, wherein the display screen 1 can be an LCD (Liquid Crystal Display) liquid crystal display, or an LED (Light Emitting Diode) light-emitting diode, OLED (Organic Light-Emitting Diode) organic light-emitting diode Diode, Micro-OLED (Micro-Organic Light-Emitting Diode) miniature organic light-emitting diode, ULED (Ultra Light Emitting Diode) extreme light-emitting diode, or DMD (Digital Micro mirror Device) digital micromirror chip, etc.

Wherein in this embodiment, the size of the display screen 1 is D1, wherein the size of the display screen 1 is defined as: the maximum size for displaying an image frame, for example, the display screen 1 has an area of a display screen, and the maximum size of this area is The size of screen 1.

In this embodiment, by limiting (B1/2-D1/2)/L1 within this range, the brightness uniformity of the displayed image is adjusted (the smaller the difference, the higher the uniformity, and the larger the difference, the lower the uniformity ), so that when the user observes images with small viewing angles, the difference in brightness of the images under different viewing angles is small, that is, when the user observes the image in the central area and the image in the edge area, the difference in brightness perceived by the user Smaller, the user's eyes are not easy to get tired when viewing the screen, which improves the user experience.

Specifically, the polarizing element 3 is the most critical and effective film layer for reflecting light in the folded optical path, the light emitted by the display screen 1 is folded between the polarizing element 3 and the light splitting element 5, and the display reflected by the polarizing element 3 The light direction of the edge area of the image on the screen 1 can basically correspond to the light direction of the edge field of view in the light source module. Specifically, the tangent value of the angle of the edge light is similar to the aperture B1 of the bearing part provided with the polarizing element 3 and the display screen 1 The ratio of the difference in size and aperture to the distance L1 from the polarizing element 3 to the display screen 1 .

Therefore, this embodiment defines the effective aperture B1 of the polarizing element 3 and the distance L1 from the polarizing element 3 to the display screen 1 in order to better simulate the incident angle of the light emitted in the image in the display screen 1 (because the incident angle cannot be accurately controlled). , and the size D1 of the display screen 1, the relationship between these three parameters makes (B1/2-D1/2)/L1 basically reflect the brightness relationship between the light brightness of the peripheral field of view and the light brightness of the central field of view.

Specifically, (B1/2-D1/2)/L1 is within this range, so that the polarizing element 3 has a good matching effect with the display screen 1, and the effective aperture provided with the polarizing element 3 has a better matching effect with the display screen 1. collocation effect. Specifically, (B1/2-D1/2)/L1 mainly adjusts the brightness of the peripheral field of view, so that the decrease range of the brightness of the peripheral field of view relative to the brightness of the central field of view is controlled within 30%, which meets the brightness of the image observed by the human eye. sensitivity.

Therefore, in this embodiment, the optical module satisfies: 0.1<A2/(C6/2)<0.5, and satisfies: 0<(B1/2-D1/2)/L1<0.8, the optical module satisfies Under the premise of compactness requirements, the brightness of the imaging image observed by the user is uniform.

In one embodiment, the distance L1 between the polarizing element 3 and the display screen 1 is 12mm-35mm.

In this embodiment, in the optical module, no matter where the polarizing element 3 is arranged in the optical module, the distance from the polarizing element 3 to the display screen 1 needs to be within this range. In this embodiment, the distance from the polarizing element 3 to the display screen 1 is controlled. On the one hand, the range of (B1/2-D1/2)/L1 is within the range of 0-0.8, reducing the brightness of light in the peripheral field of view and the brightness of the central field of view. On the other hand, by controlling the distance from the polarizing element 3 to the display screen 1, the overall optical length of the optical module is limited within a certain range, so that the optical module meets the requirements of miniaturization and light weight.

In addition, this embodiment defines the distance L1 from the polarizing element 3 to the display screen 1, and in combination with the distance A2 from the polarizing element 3 to the light splitting element 5, the distance L1 from the polarizing element 3 to the display screen 1 can be compared with the polarizing element 3 to the ratio of the distance A2 of the light splitting element 5 is defined so that the optical module has a compact structure.

In an optional embodiment, the effective aperture B1 of the polarizing element 3 is 44mm-63mm.

In this embodiment, the effective aperture supported by the polarizing element 3 is limited, on the one hand, the range of (B1/2-D1/2)/L1 is in the range of 0-0.8, reducing the brightness of the peripheral field of view light and The difference in the light brightness of the center field of view; on the other hand, after the polarizing element 3 arranged on the bearing part is processed to the optics, the light after processing can better simulate the light of the edge field of view of the optical module, so that (B1 /2-D1/2)/L1 can better reflect the transmission characteristics of light in the peripheral field of view.

According to the second aspect of the embodiments of the present application, a head-mounted display device is provided. The head-mounted display device includes: a casing; and the above-mentioned optical module.

The head-mounted display device is, for example, a VR head-mounted device, including VR glasses or a VR helmet, which is not specifically limited in this embodiment of the present application.

For the specific implementation of the head-mounted display device in the embodiment of the present application, reference may be made to the above-mentioned embodiments of the display module, and details will not be repeated here.

The optical module provided by the embodiments of the present application will be specifically described below through three embodiments.

Example 1

1, the optical module provided by the embodiment of the present application includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a light splitting element 5 and an aperture 4, wherein the first lens 21 has a direction display The second surface of the screen 1, and the first surface away from the display screen 1; the second lens 22 has a first surface adjacent to the first lens 21 and a second surface towards the display screen 1; the second lens 22 The light splitting element 5 is arranged on the second surface of the first lens 21 , and the polarizing element 3 and the first phase retarder 6 are arranged on the first surface of the first lens 21 . Wherein the setting position of the aperture 4 is the position of the human eye.

Wherein the distance A2 from the polarizing element 3 to the light-splitting element 5 is 9.6088mm, the radius of curvature C6 of the surface where the light-splitting element 5 is located is 53.86mm, and the light-splitting element 5 (wherein the light-splitting element 5 is arranged on the second lens 22, here also refers to the second The effective aperture B2 of lens 22 is 46.34mm) and the effective aperture B2 is 46.34mm; The distance L1 of polarizing element 3 to display screen 1 is 12mm, and polarizing element 3 (wherein polarizing element 3 is arranged on the first lens 21, here also It means that the effective aperture B1 of the first lens 21 is 44.5 mm), the effective aperture B1 is 44.5 mm, and the size D1 of the display screen 1 is 26 mm. The focal length F of the optical module is 15.73mm.

The optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be shown in Table 1 with reference to:

This embodiment adapts to 100 ° FOV and 26mm (small screen) image size, this embodiment A2/(C6/2)=0.357, the effective aperture B2 of the light splitting element 5 is 46.34mm, so that the optical module has a good compactness.

This case is suitable for 100°FOV and 26mm image size, and the incident angle of light in the peripheral field of view is -41°. In this embodiment (B1/2-D1/2)/L1=0.77, at this time control the light in the peripheral field of view The brightness of the display is reduced by 30% compared with that at an angle of 0° (central field of view), that is, the brightness of light in the peripheral field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 2

Referring to Fig. 2, the optical module provided by the embodiment of the present application includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a light splitting element 5 and an aperture 4, wherein the first lens 21 has a direction display The second surface of the screen 1, and the first surface away from the display screen 1; the second lens 22 has a first surface adjacent to the first lens 21 and a second surface towards the display screen 1; the second lens 22 The light splitting element 5 is arranged on the second surface of the first lens 21 , and the polarizing element 3 and the first phase retarder 6 are arranged on the first surface of the first lens 21 . Wherein the setting position of the aperture 4 is the position of the human eye.

Wherein the distance A2 from the polarizing element 3 to the light-splitting element 5 is 8.2078mm, the radius of curvature C6 of the surface where the light-splitting element 5 is located is 97.369mm, and the light-splitting element 5 (wherein the light-splitting element 5 is arranged on the second lens 22, here also refers to the second The effective aperture B2 of the lens 22 is 47.3mm) and the effective aperture B2 is 47.3mm; the distance L1 from the polarizing element 3 to the display screen 1 is 20.89mm, and the polarizing element 3 (wherein the polarizing element 3 is arranged on the first lens 21, here It also means that the effective aperture B1 of the first lens 21 is 47.6 mm), the effective aperture B1 is 47.6 mm, and the size D1 of the display screen 1 is 38 mm. The focal length F of the optical module is 23.68mm.

The optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be shown in Table 2:

This embodiment adapts to 100 ° FOV and 38mm (medium-sized screen) image surface size, this embodiment A2/(C6/2)=0.169, and the effective aperture B2 of the light splitting element 5 is 47.3mm, so that the optical module has a good compactness.

This case is suitable for 100°FOV and 38mm image size, and the incident angle of light in the peripheral field of view is -10°. In this embodiment (B1/2-D1/2)/L1=0.23, at this time control the light in the peripheral field of view The brightness of the display is reduced by 20% compared with that at an angle of 0° (central field of view), that is, the brightness of light in the peripheral field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 3

3, the optical module provided by the embodiment of the present application includes a display screen 1, a first lens 21, a second lens 22 and a third lens 23, wherein the first lens 21 is farther away from the display than the third lens 23 The screen 1 is arranged, the third lens 23 is arranged adjacent to the display screen 1 , and the second lens 22 is located between the first lens 21 and the third lens 23 .

The first lens 21 has a first surface facing away from the second lens 22, and a second surface adjacent to the second lens 22, and the second lens 22 has a first surface adjacent to the first lens 21, and a second surface adjacent to the second lens 22. The third lens 23 has a second surface adjacent to the second lens 23 , and the third lens 23 has a first surface adjacent to the second lens 22 and a second surface facing the display screen 1 .

The polarizing element 3 and the first phase retarder 6 are arranged on the second surface of the first lens 21 , and the light splitting element 5 is arranged on the second surface of the first lens 21 .

Wherein the distance A2 from the polarizing element 3 to the light-splitting element 5 is 16.089mm, the radius of curvature C6 of the surface where the light-splitting element 5 is located is 142.42mm, and the light-splitting element 5 (wherein the light-splitting element 5 is arranged on the third lens 23, here also refers to the third The effective aperture B2 of the lens 23 is 62.44mm) and the effective aperture B2 is 62.44mm; the distance L1 from the polarizing element 3 to the display screen 1 is 24.089mm, and the polarizing element 3 (wherein the polarizing element 3 is arranged on the first lens 21, here It also means that the effective aperture B1 of the first lens 21 is 62.55 mm), the effective aperture B1 of the first lens 21 is 62.55 mm, and the size D1 of the display screen 1 is 56 mm. The focal length F of the optical module is 34.7mm.

The optical parameters of the display screen 1, the first lens 21, the second lens 22, the third lens 23 and the aperture 4 can be shown in Table 3 with reference to:

This embodiment adapts to 100°FOV and 56mm (large-size screen) image surface size, this embodiment A2/(C6/2)=0.226, and the effective aperture B2 of the light splitting element 5 is 62.44mm, so that the optical module has a good compactness.

This case is suitable for 100°FOV and 56mm image size, and the incident angle of light in the peripheral field of view is -8.62°. In this embodiment (B1/2-D1/2)/L1=0.136, at this time control the light in the peripheral field of view The brightness of the display is 15% lower than that at an angle of 0° (central field of view), that is, the brightness of light in the peripheral field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

According to another aspect of the embodiments of the present application, a head-mounted display device is also provided, and the head-mounted display device includes a casing, and the above-mentioned optical module.

The above-mentioned embodiments focus on the differences between the various embodiments. As long as the different optimization features of the various embodiments do not contradict each other, they can be combined to form a better embodiment. Considering the brevity of the text, no further repeat.

Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only, rather than limiting the scope of the present invention. Those skilled in the art will appreciate that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (10)

1. An optical module, characterized in that, comprising: A lens group (2), said lens group (2) comprising at least one lens; The optical module also includes a polarizing element (3), a light splitting element (5) and a phase retarder, and either side of the lens in the lens group (2) is provided with the polarizing element (3), the light splitting element (5) ) and phase retarder; The effective aperture B2 of the light splitting element (5) is 45mm-65mm; The distance from the polarizing element (3) to the light splitting element (5) is A2; the radius of curvature of the light splitting element (5) is C6; Wherein, the optical module satisfies: 0.1<A2/(C6/2)<0.5. 2. The optical module according to claim 1, characterized in that, the distance A2 from the polarizing element (3) to the light splitting element (5) is 8mm-17mm. 3. The optical module according to claim 1, wherein the focal length of the optical module ranges from 15 mm to 35 mm. 4. The optical module according to claim 1, characterized in that, the lens group (2) includes a first lens (21) close to the human eye side, and the first lens (21) has a a first surface, and the first lens (21) has a second surface facing the side of the display screen; The polarizing element (3) is arranged on one side of the first surface, or the polarizing element (3) is arranged on one side of the second surface. 5 . The optical module according to claim 1 , wherein the lens group ( 2 ) includes a lens near the display screen, and the light splitting element ( 5 ) is arranged on the side of the lens near the display screen. 6. The optical module according to claim 1 or 4, wherein the phase retarder comprises a first phase retarder 6; The lens group (2) includes a first lens (21) close to the human eye side, the first lens (21) has a first surface facing the human eye side, and the first lens (21) has a surface facing the display a second surface on the screen side; The first phase retarder (6) is arranged on one side of the first surface, or the first phase retarder (6) is arranged on one side of the second surface, wherein the first The phase retarder (6) is arranged closer to the side of the display screen relative to the polarizing element. 7. The optical module according to claim 1, wherein the phase retarder comprises a second phase retarder; The lens group (2) includes a lens close to the display screen, and the second phase retarder is arranged on the side of the lens close to the display screen. 8. The optical module according to claim 1, characterized in that, the optical module further comprises a display screen (1), and the size of the display screen (1) is D1; The distance from the polarizing element (3) to the display screen (1) is L1; The effective aperture of the polarizing element (3) is B1; Wherein the optical module satisfies: 0<(B1/2-D1/2)/L1<0.8. 9. The optical module according to claim 8, characterized in that the distance L1 from the polarizing element (3) to the display screen (1) is 12mm-25mm. 10. A head-mounted display device, comprising: casing; and The optical module as claimed in any one of claims 1-9.

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