CN115079331A

CN115079331A - Optical module and head-mounted display device

Info

Publication number: CN115079331A
Application number: CN202210886810.6A
Authority: CN
Inventors: 姜龙; 吴玉登; 赵博刚
Original assignee: Goertek Optical Technology Co Ltd
Current assignee: Goertek Optical Technology Co Ltd
Priority date: 2022-07-26
Filing date: 2022-07-26
Publication date: 2022-09-20
Also published as: WO2024022092A1

Abstract

The invention provides an optical module and a head-mounted display device. 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, the lens group comprises a lens close to the human eye side, and the polarizing element is arranged on any side of the lens; the light splitting element and the phase retarder are arranged close to the display screen side relative to the polarization element; the effective aperture of the polarizing element is B1; the total optical length of the optical module is TTL; wherein the optical module satisfies: 1.5 < B1/TTL < 3.8.

Description

Optical module and head-mounted display device

Technical Field

The invention relates to the technical field of near-eye display imaging, in particular to an optical module and a head-mounted display device.

Background

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

In the design scheme of the pancake optical system, the distance between the polarization element and the light splitting element determines the folding distance of the optical path and the degree of the total length of the system which can be reduced, but too large distance can cause the caliber of a part provided with the light splitting element to be too large and the caliber of a part provided with the polarization element to be too large, and the overall miniaturization and balanced design of the pancake optical system are adversely affected. Therefore, how to make the length dimension of the optical module on the optical axis and the width dimension of the optical module in the direction perpendicular to the optical axis better match is a technical problem to be solved.

Disclosure of Invention

The invention aims to provide a novel technical scheme of an optical module and a head-mounted display device.

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

a lens group comprising at least one lens;

the optical module also comprises a polarizing element, a light splitting element and a phase retarder, the lens group comprises a lens close to the human eye side, and the polarizing element is arranged on any side of the lens; the light splitting element and the phase retarder are arranged close to the display screen side relative to the polarization element;

the effective aperture of the polarizing element is B1;

the total optical length of the optical module is TTL;

wherein the optical module satisfies: 1.5 < B1/TTL < 3.8.

Optionally, the total optical length TTL of the optical module is 10mm to 30 mm.

Optionally, the distance a2 from the polarizing element to the light splitting element is 4.5mm-17 mm.

Optionally, the lens group has a near-to-eye side, and the polarizing element is disposed on the near-to-eye side of the lens group; or

The lens group comprises at least two lenses, and the polarizing element is arranged between every two adjacent lenses.

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

Optionally, the phase retarder comprises a first phase retarder;

the lens group has a near-human eye side, and the first phase retarder is arranged on the near-human eye side of the lens group; or the lens group comprises at least two lenses, and the first phase delayer is arranged between the two adjacent lenses;

wherein the first phase retarder is disposed closer to a display screen side with respect to the polarizing element.

Optionally, the phase retarder comprises a second phase retarder;

the lens group has a near display screen side, and the second phase retarder is disposed on the near display screen side of the lens group.

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

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

wherein the optical module satisfies: -0.2 < (B1/2-D1/2)/L1 < 0.8.

Optionally, the distance L1 from the polarizing element to the display screen is 10mm-30 mm.

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

a housing; and

an optical module as claimed in the first aspect.

The invention has the technical effect that the optical module has better balance by controlling the ratio of the effective aperture B1 of the polarizing element to the total optical length TTL of the optical module.

Other features of the present description and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

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

Fig. 1 is a first schematic structural diagram of an optical module according to the present invention.

Fig. 2 is a second schematic structural diagram of an optical module according to the present invention.

Fig. 3 is a schematic structural diagram of an optical module according to a third embodiment of the present invention.

Fig. 4 is a schematic structural diagram of an optical module according to a fourth embodiment of the present invention.

Fig. 5 is a schematic structural diagram of an optical module according to a fifth embodiment of the present invention.

Fig. 6 is a sixth schematic structural view of the optical module according to the present invention.

Fig. 7 is a schematic structural diagram of an optical module according to a seventh embodiment of the present invention.

Fig. 8 is a schematic structural diagram eight of the optical module according to the present invention.

Fig. 9 is a schematic structural diagram nine of the optical module according to the present invention.

Description of reference numerals:

1. a display screen; 2. a lens group; 21. a first lens; 22. a second lens; 23. a third lens; 3. a polarizing element; 4. a diaphragm; 5. a light-splitting element; 6. a first phase retarder.

Detailed Description

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

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be considered a part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.

Among the design schemes of the pancake optical system, the design scheme of the pancake optical system realizes the definite transmission or reflection of light rays in a specific polarization state by utilizing the modulation effect of a polarization element on polarized light, so that the folding of an optical path is realized. In the design scheme of the pancake optical system, the distance between the polarization element and the light splitting element determines the folding distance of the optical path and the degree of the total length of the system which can be reduced, but too large distance can cause the caliber of a part provided with the light splitting element to be too large and the caliber of a part provided with the polarization element to be too large, and the overall miniaturization and balanced design of the pancake optical system are adversely affected. Therefore, how to make the length dimension of the optical module on the optical axis and the width dimension of the optical module in the direction perpendicular to the optical axis better match is a technical problem to be solved.

In view of the above technical problems, a first aspect of the present invention provides an optical module, which is a folded optical path optical structure design, and may include at least one optical lens, and may be applied to a Head Mounted Display (HMD), for example, a VR headset, such as a product that may include VR glasses or a VR helmet, and the like, which is not limited in the embodiments of the present invention.

The optical module and the head-mounted display device provided by the embodiment of the invention are described in detail below with reference to fig. 1 to 9.

An embodiment of the present invention provides an optical module, as shown in fig. 1 to 9, the optical module includes: a lens group 2, the lens group 2 comprising at least one lens; the optical module further comprises a polarizing element 3, a beam splitting element 5 and a phase retarder, the lens group 2 comprises a lens close to the human eye, and the polarizing element 3 is arranged on any side of the lens; the light splitting element 5 and the phase retarder are both disposed close to the display screen side with respect to the polarizing element 3;

the effective aperture of the polarizing element 3 is B1. The total optical length of the optical module is TTL. Wherein the optical module satisfies: 1.5 < B1/TTL < 3.8.

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

Wherein the lens group 2 comprises at least one lens, and the lens group 2 is used for magnifying and resolving light rays. For example, in a display device such as VR (Virtual Reality), in order to ensure that a user obtains an enlarged display, light needs to be enlarged, and the user obtains an identifiable enlarged image through the lens group 2. In a folded light path, the number of lenses in the optical architecture of the folded light path may be at most three, relative to a direct-lit optical architecture, taking into account that the light has been folded.

Wherein in this embodiment, in order to realize a folded optical path, the optical module further comprises a polarizing element 3, a beam splitting element 5 and a phase retarder. Specifically, the lens group 2 includes a lens on the near-human-eye side, on either side of which the polarizing element 3 is disposed; the light splitting element 5 and the phase retarder are both disposed close to the display screen side with respect to the polarizing element 3;

for example, a light splitting element 5 is provided in the lens group 2 on the side toward 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 the side of one lens of the lens group 2; a phase retarder is provided in the lens group 2 on the side facing the display screen 1, or on the side of one lens in the lens group.

In this embodiment, for example, when the light passes through the light-splitting element 5, part of the light is transmitted and the other part of the light is reflected, regardless of the fact that the light is absorbed. The light splitting element 5 may be a transflective film or a polarizing film.

Wherein the polarization element 3 is used for transmitting the P polarized light and reflecting the S polarized light; alternatively, a polarizing reflective element may be used to reflect P-polarized light through S-polarized light. Specifically, the polarizing element 3 has a polarization transmission direction, and the light can pass through the polarizing element 3 smoothly when vibrating along the polarization transmission direction, and the vibrating light in the other directions is reflected when encountering the polarizing element 3. For example, the polarizing element 3 may be a polarizing reflective film or a reflective polarizer. In the present embodiment, the specific installation position of the polarizer 3 is not limited, and the effective aperture of the polarizer 3 may be limited to B1.

In this embodiment, a phase retarder may 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 to convert circularly polarized light into linearly polarized light. For example, the phase retarder may be a quarter-wave plate.

Wherein the polarizing element 3 may be attached to the surface of a lens in the lens group 2, or the polarizing element 3 may be arranged on an optical component of the optical module, wherein the optical component may be located between two adjacent lenses, or the optical component may be located between a lens and the human eye.

Wherein the total optical length of the optical module is TTL, and the total optical length is: the surface of the lens closest to the human eye, which is disposed toward the human eye, is the distance from the image plane (display screen 1).

In this embodiment, the ratio of the effective aperture B1 of the polarizer 3 to the total optical length TTL of the optical module is defined as 1.5 < B1/TTL < 3.8, so that the total optical length of the optical module is balanced with the effective aperture of the polarizer 3, and the system balance of the optical module is better.

Specifically, the distance from the polarizing element 3 to the display screen 1 is the distance that has a strong correlation with the total optical length TTL of the optical module, that is, the distance from the polarizing element 3 to the display screen 1 has a direct correlation with the total optical length TTL of the optical module.

For example, when the polarizing element 3 is disposed on the surface of the lens group near the human eye, the distance from the polarizing element 3 to the display screen 1 is equal to the total optical length TTL of the optical module; or when the polarizing element 3 is arranged on the surface of the lens closest to the human eye and away from the human eye, the distance from the polarizing element 3 to the display screen 1 is slightly less than the total optical length TTL of the optical module (because the center thickness of the lens closest to the human eye is thinner); or when the polarizing element 3 is disposed between the human eye and the lens closest to the human eye, the distance from the polarizing element 3 to the display screen 1 may be slightly larger than the total optical length TTL of the optical module, but since the distance from the human eye and the lens closest to the human eye is shorter (the optical module is for near-eye display), the distance from the polarizing element 3 to the display screen 1 is substantially equal to the total optical length TTL of the optical module.

In summary, since the distance from the polarizer 3 to the display screen 1 may be slightly equal to the total optical length TTL of the optical module, the distance from the polarizer 3 to the display screen 1 is directly related to the total optical length TTL of the optical module, and the present embodiment defines the ratio relationship between the effective aperture B1 of the polarizer 3 and the total optical length TTL of the optical module, so as to better define the balance of the optical module.

In addition, referring to fig. 1-9, no matter whether the lens group 2 includes one lens, two lenses, or three lenses, the optical module is provided with the polarizing element 3, wherein the polarizing element 3 is disposed on one side of the lens closest to the human eye, and the lens closest to the human eye and the human eye are generally fixedly disposed, so that the disposition position of the polarizing element 3 in this embodiment is relatively fixed to the human eye, that is, a relatively fixed position is selected in this embodiment, and the balance of the optical module is defined for the ratio relationship between the common plane (the surface on which the polarizing element 3 is disposed) of the optical module structure and the total optical length TTL of the optical module.

The position of the polarization element 3 of this embodiment is relatively fixed, namely the surface on which the polarization element 3 is disposed is relatively fixed. Specifically, when the lens group 2 includes two lenses, wherein the lens close to the display screen 1 is adjustable in distance from the display screen 1 according to the size of the display screen 1; when the lens group 2 includes three lenses, the setting position of the lens between the two lenses is also adjustable, wherein the setting position of the lens is related to the aperture of the lens, and when the setting position of the lens is changed, the aperture of the corresponding lens is also correspondingly adjustable.

Thus, in general, when the lens group 2 includes at least two lenses, the arrangement position of the lens closest to the human eye with respect to the other lenses is fixed. Therefore, in the present embodiment, a relatively fixed common plane (the surface on which the polarization element 3 is disposed) of the optical module structure is selected for representing the effective aperture of the polarization element 3, so that the present embodiment controls the balance of the optical module by defining the ratio of B1 to TTL.

The balance of the optical module in this embodiment is mainly embodied in the balance control of the total optical length of the optical module and the effective aperture of the polarizer, and the optical module in this embodiment is a folding optical structure, and the number of lenses of the optical module in this embodiment is small compared to a direct-illumination optical structure, so the optical module in this embodiment is also light in weight. Therefore, it can be said that the balance of the optical module of the present embodiment is realized by the balance control of the total optical length of the optical module, the effective aperture of the optical module, and the weight of the optical module.

In summary, in the present embodiment, a relatively fixed ratio of the common surface (the surface on which the polarizer 3 is disposed) of the optical module structure to the total optical length TTL of the optical module is selected, so that the balance of the optical module can be better represented, that is, by defining the ratio relationship between B1 and TTL, the total optical length of the optical module and the matching relationship between the total optical length and the effective aperture of the polarizer 3 can be better represented, that is, by defining the ratio relationship between B1 and TTL, the total optical length of the optical module and the matching relationship between the total optical length and the effective aperture of the optical module can be better represented.

Therefore, the embodiment of the invention considers the matching relationship between the effective aperture B1 of the polarizer 3 and the effective aperture of the optical module, and considers the ratio relationship between the effective aperture B1 of the polarizer 3 and the total optical length TTL of the optical module, so that the structure of the optical module is balanced.

It should be noted that, in the embodiment of the present invention, a person skilled in the art may flexibly adjust the ratio relationship between the effective aperture of the optical module, which is provided with the polarizing element 3, and the total optical length of the optical module according to specific needs, as long as the ratio relationship is controlled within a preset range.

For example, the B1/TTL can range from 2 to 3.5.

For another example, the B1/TTL can range from 2.5 to 3.

For another example, the B1/TTL can be in the range of 3 to 3.5.

Within the above ratio ranges, a balanced optical module system can be realized.

Of course, in the embodiment of the present invention, the relation between the effective aperture of the polarizer 3 in the optical module and the optical total length of the optical module is not limited to the above three examples, and those skilled in the art can flexibly adjust the effective aperture and the optical total length as needed, and the embodiment of the present invention is not limited thereto.

In one embodiment, the total optical length TTL of the optical module is 10mm-30 mm.

In an alternative embodiment, the effective aperture B1 of the polarizer 3 is 40mm to 65 mm.

In this embodiment, the effective aperture of the polarizer 3 and the optical overall length of the optical module are defined such that the optical overall length of the optical module is controlled in balance with the effective aperture of the lens (or optical component) in the optical module.

In this embodiment, the total optical length TTL of the optical module is limited, so that the balance and compactness of the optical module can be controlled, and the volume of the optical module is reduced.

In one embodiment, the distance A2 from the polarizing element 3 to the light splitting element 5 is 4.5mm-17 mm.

In this embodiment, the distance from the polarizing element 3 to the light splitting element 5 is defined, that is, the length of the folded optical path in the optical module is defined. The longer the folded optical path from the polarizing element 3 to the light splitting element 5, the longer the distance from the polarizing element 3 to the light splitting element 5, and the smaller the overall optical length of the optical module. Due to the presence of the folded optical path, the folded optical path equivalently increases the number of lenses and the doubled power characteristic provided by the reflecting surface (reflection of the beam splitting element 5, or reflection of the polarizing element 3), so that the overall optical length of the optical module is smaller.

Further, considering that the longer the distance a2 between the light splitting element 5 and the polarizing element 3 is, the larger the effective aperture B1 of the polarizing element 3 is, and specifically, since the light emitted from the display screen 1 is transmitted in an extensional manner, and the folded optical path is not transmitted in parallel to the optical axis during transmission, the longer the distance a2 between the light splitting element 5 and the polarizing element 3 is, the larger the effective aperture B1 of the polarizing element 3 is. In addition, the larger the effective aperture B1 of the polarizer 3 is, the larger the aperture of the optical module system is, and the negative effect on the system balance is caused.

Therefore, the present embodiment defines the distance a2 between the polarizer 3 and the beam splitter 5, so that the total optical length of the optical module is defined in a suitable range, and the effective aperture of the polarizer 3 is defined in a suitable range, and therefore, the distance a2 between the polarizer 3 and the beam splitter 5 is defined, which can effectively control the ratio of the effective aperture B1 of the polarizer 3 to the total optical length TTL of the optical module, so that the total optical length of the optical module and the effective aperture of the lens (or optical component) in the optical module are controlled in a balanced manner.

In an alternative embodiment, the effective aperture B2 of the light-splitting element 5 is 40mm to 65 mm.

In this embodiment, the effective aperture of the light splitting element 5 is defined as B2, wherein the effective aperture of the light splitting element 5 is defined as B2 and the distance a2 between the polarizing element 3 and the light splitting element 5, which are in an interacting relationship. Specifically, the larger the effective aperture B2 of the light splitting element 5 is, the larger the distance between the polarizing element 3 and the light splitting element 5 can be allowed to be, so as to increase the folded optical path of the light between the polarizing element 3 and the light splitting element 5, and when the folded optical path of the light between the polarizing element 3 and the light splitting element 5 is prolonged, the total optical length of the optical module is greatly shortened; however, the larger the effective aperture B2 of the beam splitter 5 is, the larger the effective aperture of the optical module becomes, and the total optical length of the optical module and the degree of matching with the effective aperture of the optical module decrease.

Therefore, in consideration of the relationship among the effective aperture B2 of the optical splitter 5, the total optical length of the optical module, and the effective aperture of the optical module, the present embodiment limits the effective aperture B2 of the optical splitter 5 within this range, so that the total optical length of the optical module and the effective aperture of the optical module are controlled in a balanced manner.

In one embodiment, the lens group 2 has a near-eye side, and the polarizing element 3 is disposed on the near-eye side of the lens group 2; or

The lens group 2 includes at least two lenses, and the polarizing element 3 is disposed between adjacent two lenses.

In this embodiment, the position where the polarizing element 3 is disposed is defined so that the effective aperture of the first carrier member provided with the polarizing element 3 satisfies the difference relationship of B1/TTL.

Specifically, referring to fig. 1 to 9, the lens groups 2, whether including one lens, two lenses, three lenses, or the like, have a near-human-eye side, and the lens groups 2 have lenses disposed near the human-eye side. A polarizing element 3 is provided on the near-to-human-eye side of the lens. For example, the lens has a surface which is arranged towards the human eye and on which the polarizing element 3 is arranged, or the polarizing element 3 is arranged between the lens and the human eye. Wherein the polarizing element 3 can be positioned between the lens and the human eye by means of optical components.

Referring to fig. 1, 2, 5 and 8, the lens group comprises at least two lenses, wherein the at least two lenses comprise the lens closest to the human eye, wherein the lens closest to the human eye, i.e. the lens further away from the display screen 1, is used to directly transmit light to the human eye and to image in the human eye.

For example, referring to fig. 1 and 2, the at least two lenses comprise a first lens 21 and a second lens 22, wherein the first lens 21 is arranged close to the human eye, the second lens 22 is arranged close to the display screen 1, the polarizing element 3 is arranged between the first lens 21 and the second lens 22, for example, the polarizing element 3 is arranged on the surface of the first lens 21 facing away from the human eye; or, for another example, an optical member is additionally provided between the first lens 21 and the second lens 22, and the polarizing element 3 is provided on the optical member;

for example, referring to fig. 5 and 8, the at least two lenses include a first lens 21, a second lens 22, and a third lens 23, wherein the first lens 21 is disposed near the human eye, the second lens 22 is disposed between the first lens 21 and the third lens 23, and the third lens 23 is disposed closest to the display screen 1. Wherein a polarizing element 3 is arranged between the second lens 22 and the first lens 21.

The present embodiment does not limit the specific position of the polarizer 3, so that the effective aperture of the first carrier provided with the polarizer 3 satisfies the difference relationship of B1/TTL.

In one embodiment, the lens group 2 has a near display screen side, and the light splitting element 5 is disposed on the near display screen side of the lens group 2.

Specifically, the lens groups 2, whether including one lens, two lenses, three lenses, or the like, have a side close to the display screen 1, wherein the lens groups 2 each have a lens disposed close to the display screen 1 side. A light splitting element 5 is provided on the near display screen 1 side of the lens. For example, the lens has a surface disposed toward the display screen 1, on which surface the light-splitting element 5 is disposed, or the light-splitting element 5 is disposed between the lens and the display screen 1. Wherein the light-splitting element 5 can be positioned between the lens and the display screen 1 by means of optical components.

Referring to fig. 7, the lens group 2 includes only one lens, in which the light splitting element 5 is disposed on the near display screen 1 side of the lens. For example, a light-splitting element 5 is attached to the surface of the lens facing the display screen 1. Alternatively, an optical member is provided between the lens and the display screen 1, and the spectroscopic element 5 is attached to the optical member.

In this embodiment, the specific installation position of the light splitting element 5 is not particularly limited, as long as the effective aperture of the light splitting element 5 is limited within a reasonable range, and the architecture of the optical module has balance.

For example, referring to fig. 1-4, the at least two lenses include a first lens 21 and a second lens 22, wherein the first lens 21 is disposed adjacent to the human eye side and the second lens 22 is disposed adjacent to the display screen 1. Wherein the light-splitting element 5 is arranged on the surface of the second lens 22 facing the display screen 1, i.e. facing away from the human eye.

For example, as shown in fig. 5, the at least two lenses include a first lens 21, a second lens 22, and a third lens 23, wherein the first lens 21 is disposed near the human eye, the second lens 22 is disposed between the first lens 21 and the third lens 23, and the third lens 23 is disposed farthest from the human eye. A light-splitting element 5 is arranged in the third lens 23 on the surface facing the display screen 1.

The present embodiment does not limit the specific position of the light splitting element 5, as long as the architecture of the optical module is balanced.

In one embodiment, the phase retarder comprises a first phase retarder 6; the lens group 2 has a near-to-eye side, and the first phase retarder 6 is arranged on the near-to-eye side of the lens group 2; or the lens group 2 comprises at least two lenses, and the first phase retarder 6 is arranged between two adjacent lenses;

wherein the first phase retarder 6 is disposed closer to the display screen side with respect to the polarizing element 3.

Specifically, referring to fig. 3, 4, 5, 7, and 9, the lens groups 2, whether the lens group 2 includes one lens, two lenses, three lenses, or the like, have a near-human-eye side, and the lens groups 2 have lenses disposed near the human-eye side. A first phase retarder 6 is provided on the near-to-human-eye side of the lens. For example, the lens has a surface disposed toward the human eye on which the first phase retarder 6 is disposed, or the first phase retarder 6 is disposed between the lens and the human eye.

Referring to fig. 1 and 2, the at least two lenses include a first lens 21 and a second lens 22, wherein the first lens 21 is disposed near the human eye, the second lens 22 is disposed near the display screen 1, and the first phase retarder 6 is disposed between the first lens 21 and the second lens 22.

In this embodiment, the first phase retarder 6 is disposed closer to the display screen side than the polarizing element 3. For example, the first phase retarder 6 and the polarizing element 3 are both disposed on a first surface (toward the human eye) of the first lens 21, the first phase retarder 6 is disposed closer to the first lens 21 with respect to the polarizing element 3, or the first phase retarder 6 and the polarizing element 3 are both disposed on a second surface (toward the second lens 22) of the first lens 21, the first phase retarder 6 is disposed farther from the first lens 21 with respect to the polarizing element 3.

The polarization state of the light passing through the first phase retarder 6 is changed, wherein the light passing through the first phase retarder 6 for the first time is reflected by the polarization element 3, the reflected light is processed by the light splitting element 5, and passes through the first phase retarder 6 again, wherein the light passing through the first phase retarder 6 for the second time is transmitted by the polarization element 3 and transmitted to human eyes.

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

In this embodiment, the lens groups 2, whether they include one lens, two lenses, three lenses, or the like, have a side close to the display screen 1, wherein the lens groups 2 each have a lens disposed close to the display screen 1 side. A second phase retarder is arranged on the side of the lens near the display screen 1. For example, the lens has a surface disposed toward the display screen 1 on which a second two-bit retarder is disposed, or a second phase retarder is disposed between the lens and the display screen 1. Wherein the second phase retarder is arranged closer to the display screen side than the light splitting element 5.

In one embodiment, the optical module further comprises a display screen 1, wherein the size of the display screen 1 is D1; the distance from the polarizing element to the display screen 1 is L1; wherein the optical module satisfies: -0.2 < (B1/2-D1/2)/L1 < 0.8.

In this embodiment, the optical module further includes a display screen 1, wherein the display screen 1 may be an lcd (liquid Crystal display) lcd, or an led (Light Emitting Diode), an OLED (Organic Light-Emitting Diode), a Micro-OLED (Micro-Organic Light-Emitting Diode), an uled (ultra Light Emitting Diode), or a dmd (digital micromirror 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 picture, for example, the display screen 1 has an area for displaying a picture, the maximum size of which is the size of the display screen 1.

In this embodiment, by defining (B1/2-D1/2)/L1 within this range, the brightness uniformity of the displayed image is adjusted (the smaller the difference is, the higher the uniformity is, the larger the difference is, the lower the uniformity is), so that when the user observes the images at different viewing angles, the brightness difference of the images at different viewing angles is smaller, that is, when the user observes the images in the central area and the images in the edge area, the brightness difference perceived by the user is smaller, the eyes of the user do not easily get tired when the user observes the screen, and the user experience is improved.

Specifically, the polarizing element 3 is used as the most critical and most effective film layer for reflecting light in the folded light path, the light emitted from the display screen 1 is folded between the polarizing element 3 and the light splitting element 5, the light direction of the image edge area in the display screen 1 reflected by the polarizing element 3 can substantially correspond to the light direction of the edge field in the light source module, specifically, the tangent value of the angle of the edge light is approximate to the difference between the effective aperture B1 of the polarizing element 3 and the size aperture of the display screen 1, and the ratio of the distance L1 from the polarizing element 3 to the display screen 1.

Therefore, in order to better simulate the incident angle of the light emitted from the image on the display screen 1 (because the incident angle cannot be accurately controlled), the relationship among the effective aperture B1 of the polarizer 3, the distance L1 from the polarizer 3 to the display screen 1, and the size D1 of the display screen 1 is defined, so that the relationship between the brightness of the light in the edge field and the brightness of the light in the central field can be basically reflected by (B1/2-D1/2)/L1.

Specifically, the (B1/2-D1/2)/L1 is in this range, so that the polarizer 3 and the display screen 1 have good matching effect, and the effective aperture of the polarizer 3 and the display screen 1 have good matching effect. Specifically, (B1/2-D1/2)/L1 mainly adjusts the brightness of the edge field so that the decrease range of the brightness of the edge field relative to the brightness of the central field is controlled within 30%, and the sensitivity of human eyes for observing the brightness of the image is satisfied.

In this embodiment, therefore, the optical module satisfies: 1.5 < B1/TTL < 3.8, and satisfies: 0.2 < (B1/2-D1/2)/L1 < 0.8, and the optical module can make the brightness of the imaged image visually observed by the user uniform, namely the brightness of the edge field and the brightness of the central field are uniform on the premise of meeting the requirement of balance.

In one embodiment, the distance L1 from the polarizing element 3 to the display screen 1 is 10mm-30 mm.

In an alternative embodiment, the size D1 of the display screen 1 is 20mm-60 mm.

In this embodiment, in the optical module, no matter where the polarizing element 3 is disposed in the optical module, it is necessary to make the distance from the polarizing element 3 to the display screen 1 within this range. The present embodiment controls the distance from the polarizer 3 to the display screen 1, so that (B1/2-D1/2)/L1 satisfies-0.2 < (B1/2-D1/2)/L1 < 0.8, and reduces the difference between the brightness of the light in the edge field and the brightness of the light in the center field; on the other hand, the distance from the polarizing element 3 to the display screen 1 is controlled, so that the total optical length of the optical module is limited within a certain range, and the optical module meets the requirements of miniaturization and light weight.

In this embodiment, the size D1 of the display screen 1 is defined so that the lens assembly 2 in the optical module can be matched with display screens 1 of different sizes. In addition, the size D1 of the display screen 1 is controlled so that (B1/2-D1/2)/L1 satisfies-0.2 < (B1/2-D1/2)/L1 < 0.8, and the difference between the brightness of the light in the edge field and the brightness of the light in the center field is reduced.

According to a second aspect of the embodiments of the present invention, there is provided a head mounted display device. The head mounted display device includes: a housing; and an optical module as described above. For example, a head-mounted display device comprises a housing, and the optical module of the first aspect; or the head-mounted display device comprises a shell and the optical module of the second aspect.

The head-mounted display device is, for example, a VR head-mounted device, which includes VR glasses or a VR helmet, and the like, and this is not particularly limited in this embodiment of the present invention.

The specific implementation of the head-mounted display device according to the embodiment of the present invention may refer to the above embodiments of the display module, and will not be described herein again.

The optical module provided by the embodiment of the invention is specifically described by nine embodiments.

Example 1

Referring to fig. 1, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a second surface disposed adjacent to the second lens 22 and a first surface disposed toward a human eye; the second lens 22 has a first surface disposed adjacent to the first lens 21, and a second surface facing the display screen 1;

a light splitting element 5 is disposed on the second surface of the second lens 22, and a polarizing element 3 and a first phase retarder 6 are disposed on the second surface of the first lens 21. Wherein the diaphragm 4 is arranged at the position of the human eye.

The effective aperture B1 of the lens module in which the polarizing element 3 is disposed (in which the polarizing element 3 is disposed on the first lens 21, which also means that the effective aperture B1 of the first lens 21 is 49.6 mm) is 49.6mm, and the total optical length TTL of the optical module is 21.4 mm; the size D1 of the display screen 1 is 34 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 18.9 mm. The effective aperture B2 of the light-splitting element 5 (in which the light-splitting element 5 is disposed on the second lens 22, also referred to herein as the effective aperture B2 of the second lens 22 being 50.8 mm) is 50.8 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 7.5 mm.

Wherein the optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be referred to table 1:

the scheme is suitable for the FOV of 100 degrees and the image surface size of 34mm (a small-size screen), B1/TTL =2.318 is adopted in the scheme, and the optical module has better system balance in the scheme.

The image plane size of 100 degrees FOV and 34mm is adapted in the present case, the light incidence angle of the marginal field of view is-20.1 degrees, in the present case (B1/2-D1/2)/L1=0.333, at this time, the brightness of the light of the marginal field of view is controlled to be reduced by 25% -30% compared with the brightness of the light of the marginal field of view under the angle of 0 degrees (central field of view), that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 2

Referring to fig. 2, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a second surface disposed adjacent to the second lens 22, and a first surface facing the human eye; the second lens 22 has a first surface disposed adjacent to the first lens 21, and a second surface facing the display screen 1;

Wherein the effective aperture B1 of the polarizer 3 (wherein the polarizer 3 is disposed on the first lens 21, which is also referred to herein as the effective aperture B1 of the first lens 21 being 48 mm) is 48mm, and the total optical length TTL of the optical module is 25 mm; the size D1 of the display screen 1 is 46 mm; the distance L1 from the polarizing element 3 to the display screen 1 was 21.1 mm. The effective aperture B2 of the light-splitting element 5 (in which the light-splitting element 5 is disposed on the second lens 22, also referred to herein as the effective aperture B2 of the second lens 22 being 51 mm) is 51 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 8.49 mm.

Wherein the optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be referred to table 2:

the embodiment adapts to 100 ° FOV and 46mm (medium screen) image plane size, B1/TTL =1.92 in the embodiment, and the optical module has better system balance in the embodiment.

The image plane size of 100 degrees FOV and 46mm is adapted in the present case, the light incidence angle of the marginal field of view is-0.9 degrees, in the present case (B1/2-D1/2)/L1=0.095, at this time, the brightness of the light of the marginal field of view is controlled to be reduced by 10% compared with the brightness of the light of the 0 degree angle (central field of view), that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 3

Referring to fig. 3, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a second surface disposed adjacent to the second lens 22, and a first surface facing the human eye; the second lens 22 has a first surface disposed adjacent to the first lens 21, and a second surface facing the display screen 1;

a light splitting element 5 is disposed on the second surface of the second lens 22, and a polarizing element 3 and a first phase retarder 6 are disposed on the first surface of the first lens 21. Wherein the diaphragm 4 is arranged at the position of the human eye.

The effective aperture B1 of the optical module, in which the polarizing element 3 is arranged (wherein the polarizing element 3 is arranged on the first lens 21, and the effective aperture B1 of the first lens 21 is 44.5 mm) is 44.5mm, and the total optical length TTL of the optical module is 12 mm; the size D1 of the display screen 1 is 26 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 12 mm. The effective aperture B2 of the light splitting element 5 (in which the light splitting element 5 is provided on the second lens 22, which also means herein that the effective aperture B2 of the second lens 22 is 46.34 mm) is 46.34 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 9.6088 mm.

Wherein the optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be referred to table 3:

the embodiment adapts to 100 degrees of FOV and 26mm (small size screen) image plane size, B1/TTL =3.708 in the embodiment, and the optical module in the embodiment has better system balance.

The image plane size of 100 degrees FOV and 26mm is adapted in the present case, the light incidence angle of the marginal field of view is-41 degrees, in the present case (B1/2-D1/2)/L1=0.77, at this time, the brightness of the display brightness of the marginal field of view is controlled to be reduced by 30% compared with the brightness of the marginal field of view under the angle of 0 degrees (central field of view), that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 4

Referring to fig. 4, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a second surface disposed adjacent to the second lens 22, and a first surface facing the human eye; the second lens 22 has a first surface disposed adjacent to the first lens 21, and a second surface facing the display screen 1;

The effective aperture B1 of the optical module, in which the polarizing element 3 is arranged (wherein the polarizing element 3 is arranged on the first lens 21, and the effective aperture B1 of the first lens 21 is 47.6 mm), is 47.6mm, and the total optical length TTL of the optical module is 20.89 mm; the size D1 of the display screen 1 is 38 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 20.89 mm. The effective aperture B2 of the light-splitting element 5 (in which the light-splitting element 5 is provided on the second lens 22, also referred to herein as the effective aperture B2 of the second lens 22 being 47.3 mm) is 47.3 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 8.2078 mm.

Wherein the optical parameters of the display screen 1, the first lens 21, the second lens 22 and the diaphragm 4 can be referred to table 4:

the embodiment adapts to 100 ° FOV and 38mm (medium screen) image plane size, in the embodiment, B1/TTL =2.28, and the optical module in the embodiment has better system balance.

The image plane size of 100 degrees FOV and 38mm is adapted in the present case, the light incidence angle of the marginal field of view is-10 degrees, in the present case (B1/2-D1/2)/L1=0.23, and at this time, the display brightness of the light of the marginal field of view is controlled to be reduced within 20% of the brightness under the angle (central field of view) of 0 degrees, that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 5

Referring to fig. 5, the optical module according to the embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a third lens 23, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 is disposed closest to human eyes, the third lens 23 is disposed closest to the display screen 1, and the second lens 22 is located between the first lens 21 and the third lens 23.

Wherein the first lens 21 has a second surface disposed adjacent to the second lens 22, and a first surface facing the human eye side; the third lens 23 has a first surface disposed adjacent to the second lens 22, and a second surface facing the display screen 1;

a light splitting element 5 is disposed on the second surface of the third lens 23, and a polarizing element 3 and a first phase retarder 6 are disposed on the second surface of the first lens 21. Wherein the diaphragm 4 is arranged at the position of the human eye.

The effective aperture B1 of the optical module in which the polarizing element 3 is disposed (in which the polarizing element 3 is disposed on the first lens 21, which also means that the effective aperture B1 of the first lens 21 is 40.26 mm) is 40.26mm, and the total optical length TTL of the optical module is 13.6713 mm; the size D1 of the display screen 1 is 26 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 11.1583 mm. The effective aperture B2 of the light splitting element 5 (in which the light splitting element 5 is disposed on the third lens 23, which is also referred to herein as the effective aperture B2 of the third lens 23 being 44.05 mm) is 44.05 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 9.6613 mm.

The optical parameters of the display screen 1, the first lens 21, the second lens 22, the third lens 23 and the diaphragm 4 can be shown in table 5:

the embodiment adapts to 100 degrees of FOV and 26mm (small size screen) image plane size, B1/TTL =2.945 in the embodiment, and the optical module in the embodiment has better system balance.

The image plane size of 100 degrees FOV and 26mm is adapted in the present case, the light incidence angle of the marginal field of view is-37.1 degrees, in the present case (B1/2-D1/2)/L1=0.64, at this time, the display brightness of the marginal field of view light is controlled to be reduced within 30% of the brightness under the angle (central field of view) of 0 degrees, that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 6

Referring to fig. 6, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a second surface disposed adjacent to the second lens 22, and a first surface facing the human eye; the second lens 22 has a first surface disposed adjacent to the first lens 21, and a second surface facing the display screen 1;

The effective aperture B1 of the optical module in which the polarizing element 3 is disposed (in which the polarizing element 3 is disposed on the first lens 21, which also means that the effective aperture B1 of the first lens 21 is 53.7 mm) is 53.7mm, and the total optical length TTL of the optical module is 20.255 mm; the size D1 of the display screen 1 is 44.9 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 20.255 mm. The effective aperture B2 of the light-splitting element 5 (in which the light-splitting element 5 is disposed on the second lens 22, also referred to herein as the effective aperture B2 of the second lens 22 being 58.1 mm) is 58.1 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 16.755 mm.

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 6:

the embodiment adapts to 100 ° FOV and 44.9mm (middle size screen) image plane size, in the embodiment, B1/TTL =2.651, and the optical module in the embodiment has better system balance.

The case of the scheme is adapted to the FOV of 100 degrees and the image surface size of 44.9mm, the light incidence angle of the peripheral field is-15.7 degrees, and in this embodiment (B1/2-D1/2)/L1=0.217, at this time, the display brightness of the light of the peripheral field is controlled to be reduced by less than 25% compared with the brightness of the light of the peripheral field under the angle of 0 degrees (central field), that is, the light brightness of the peripheral field is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 7

Referring to fig. 7, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a first surface facing a human eye side, and a second surface facing the display screen 1 side.

A light splitting element 5 is disposed on the second surface of the first lens 21, and a polarizing element 3 and a first phase retarder 6 are disposed on the first surface of the first lens 21. Wherein the diaphragm 4 is arranged at the position of the human eye.

The effective aperture B1 of the optical module provided with the polarizing element 3 (wherein the polarizing element 3 is arranged on the first lens 21, and the effective aperture B1 of the first lens 21 is 42.36 mm) is 42.36mm, and the total optical length TTL of the optical module is 12.8587 mm; the size D1 of the display screen 1 is 25 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 12.887 mm. The effective aperture B2 of the light splitting element 5 (in which the light splitting element 5 is disposed on the first lens 21, also referred to herein as the effective aperture B2 of the first lens 21 being 42.36 mm) is 42.36 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 6.3874 mm.

Wherein the optical parameters of the display screen 1, the first lens 21 and the diaphragm 4 can be seen with reference to table 7:

the embodiment adapts to 100 ° FOV and 25mm (small screen) image plane size, in the embodiment, B1/TTL =3.294, and the optical module in the embodiment has better system balance.

The case of the scheme is adapted to the FOV of 100 degrees and the image surface size of 25mm, the light incidence angle of the marginal field of view is-30.51 degrees, in this embodiment (B1/2-D1/2)/L1= 0.675), and at this time, the brightness of the light of the marginal field of view is controlled to be reduced within 25% -30% of the brightness of the light of the marginal field of view under the condition of 0 degree (central field of view), namely, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 8

Referring to fig. 8, the optical module according to the embodiment of the present invention includes a display screen 1, a first lens 21, a second lens 22, a third lens 23, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 is disposed closest to human eyes, the third lens 23 is disposed closest to the display screen 1, and the second lens 22 is located between the first lens 21 and the third lens 23.

The effective aperture B1 of the optical module, in which the polarizing element 3 is disposed (in which the polarizing element 3 is disposed on the first lens 21, and the effective aperture B1 of the first lens 21 is 62.55 mm) is 62.55mm, and the total optical length TTL of the optical module is 26.957 mm; the size D1 of the display screen 1 is 56 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 24.089 mm. The effective aperture B2 of the light splitting element 5 (in which the light splitting element 5 is disposed on the third lens 23, which is also referred to herein as the effective aperture B2 of the third lens 23 being 62.44 mm) is 62.44 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 16.089 mm.

The optical parameters of the display screen 1, the first lens 21, the second lens 22, the third lens 23 and the diaphragm 4 can be shown in table 8:

the embodiment adapts to 100 ° FOV and 56mm (large size screen) image plane size, B1/TTL =2.32 in the embodiment, and the optical module in the embodiment has better system balance.

The image plane size of 100 degrees FOV and 56mm is adapted in the present case, the light incidence angle of the marginal field of view is-8.62 degrees, in the present case (B1/2-D1/2)/L1=0.136, at this time, the display brightness of the marginal field of view light is controlled to be reduced within 15% of the brightness under the angle (central field of view) of 0 degrees, that is, the light brightness of the marginal field of view is reduced, and the uniformity of the brightness of the display screen 1 is improved.

Example 9

Referring to fig. 9, an optical module according to an embodiment of the present invention includes a display screen 1, a first lens 21, a polarizing element 3, a beam splitting element 5, and a diaphragm 4, where the first lens 21 has a first surface facing a human eye side and a second surface facing the display screen 1 side.

An effective aperture B1 of the optical module in which the polarizing element 3 is disposed (in which the polarizing element 3 is disposed on the first lens 21, also referred to herein as an effective aperture B1 of the first lens 21 being 44.34 mm) is 44.34mm, and a total optical length TTL of the optical module is 12.8587 mm; the size D1 of the display screen 1 is 25 mm; the distance L1 from the polarizing element 3 to the display screen 1 is 12.887 mm. The effective aperture B2 of the spectroscopic element 5 (in which the spectroscopic element 5 is disposed on the first lens 21, which is also referred to herein as the effective aperture B2 of the first lens 21 being 44.34 mm) is 44.34 mm. The distance a2 from the polarizing element 3 to the light-splitting element 5 was 4.9943 mm.

Wherein the optical parameters of the display screen 1, the first lens 21 and the diaphragm 4 can be seen with reference to table 9:

the embodiment adapts to 100 ° FOV and 25mm (small size screen) image plane size, B1/TTL =1.637 in the embodiment, and the optical module in the embodiment has better system balance.

The scheme is adaptive to the FOV of 100 degrees and the size of an image plane of 46mm, the light incidence angle of the marginal field of view is 5 degrees, in this embodiment (B1/2-D1/2)/L1= -0.031), and at the moment, the brightness of the light in the marginal field of view is controlled to be reduced by less than 10% compared with the brightness of the light in the 0 degree (central field of view), namely, the brightness of the light in the marginal 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 invention, there is also provided a head-mounted display device, which includes a housing and the optical module as described above.

In the above embodiments, the differences between the embodiments are described with emphasis, and different optimization features between the embodiments may be combined to form a better embodiment as long as the differences are not contradictory, and in consideration of the brevity of the text, no further description is given here.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for the purpose of illustration and is not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may 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

1. An optical module, comprising:

a lens group (2), the lens group (2) comprising at least one lens;

the optical module further comprises a polarizing element (3), a light splitting element (5) and a phase retarder, the lens group (2) comprises a lens close to the human eye side, and the polarizing element (3) is arranged on any side of the lens; the light splitting element (5) and the phase retarder are both arranged close to the display screen side relative to the polarization element (3);

the effective aperture of the polarizing element (3) is B1;

the total optical length of the optical module is TTL;

wherein the optical module satisfies: 1.5 < B1/TTL < 3.8.

2. The optical module of claim 1 wherein the total optical length TTL is 10mm to 30 mm.

3. An optical module according to claim 1 or 2, characterized in that the distance a2 from the polarizing element (3) to the light-splitting element (5) is 4.5mm-17 mm.

4. Optical module according to claim 1, in which the lens group (2) has a near-to-eye side, the polarizing element (3) being arranged on the near-to-eye side of the lens group (2); or

The lens group (2) comprises at least two lenses, and the polarizing element (3) is arranged between two adjacent lenses.

5. Optical module according to claim 1, characterized in that the lens group (2) has a near display screen side, on which the light-splitting element (5) is arranged on the near display screen side of the lens group (2).

6. An optical module according to claim 1 or 4, characterized in that the phase retarder comprises a first phase retarder (6);

the lens group (2) has a near-to-human eye side, and the first phase retarder (6) is arranged on the near-to-human eye side of the lens group (2); or the lens group (2) comprises at least two lenses, and the first phase delayer (6) is arranged between two adjacent lenses;

wherein the first phase retarder (6) is disposed closer to the display screen side with respect to the polarizing element (3).

7. The optical module of claim 1 wherein the phase retarder comprises a second phase retarder;

the lens group (2) has a near display screen side, and the second phase retarder is disposed on the near display screen side of the lens group.

8. Optical module according to claim 1, characterized in that it further comprises a display screen (1), the size of said display screen (1) being D1;

the distance from the polarizing element (3) to the display screen (1) is L1;

wherein the optical module satisfies: -0.2 < (B1/2-D1/2)/L1 < 0.8.

9. An optical module according to claim 8, characterized in that the distance L1 from the polarizing element (3) to the display screen (1) is 10mm-30 mm.

10. A head-mounted display device, comprising:

a housing; and

the optical module of any one of claims 1-9.