CN112051671A

CN112051671A - Near-eye display optical machine and method thereof and near-eye display equipment

Info

Publication number: CN112051671A
Application number: CN201910489112.0A
Authority: CN
Inventors: 郝希应; 陈杭; 郑光; 胡增新
Original assignee: Sunny Optical Zhejiang Research Institute Co Ltd
Current assignee: Sunny Optical Zhejiang Research Institute Co Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2020-12-08
Anticipated expiration: 2039-06-06
Also published as: CN112051671B

Abstract

A near-eye display optical machine and a method thereof and a near-eye display device are provided. The near-eye display optical machine comprises an image source unit, a polarization beam splitting unit, a perspective reflection unit, a polarization conversion unit and a lens group unit, wherein the image source unit is used for emitting image light along an emission path. The lens group unit and the polarization beam splitting unit are both arranged on the emission path of the image source unit. The included angle between the polarization beam splitting unit and the optical viewing axis of the near-eye display optical machine is larger than 45 degrees, and the polarization beam splitting unit is used for reflecting the first polarization image light and transmitting the second polarization image light. The perspective reflection unit is disposed on a reflection side of the polarization beam splitting unit, and is configured to reflect a part or all of the first polarized image light back to the polarization beam splitting unit and allow a part of the ambient light to pass through. The polarization conversion unit is arranged between the polarization beam splitting unit and the perspective reflection unit and is used for converting the first polarization image light into the second polarization image light after the first polarization image light passes through the second polarization image light twice.

Description

Near-eye display optical machine and method thereof and near-eye display equipment

Technical Field

The invention relates to the technical field of augmented reality, in particular to a near-eye display optical machine, a near-eye display method and near-eye display equipment.

Background

Augmented Reality (AR) is also called Augmented Reality or mixed Reality, and is a technology for superimposing a virtual object on a real environment and performing interaction, and an image of the virtual object and an image of the real environment are transmitted to eyes of a user, so that the user obtains experience of fusion of virtual Reality and Reality. Near-eye display devices capable of realizing augmented reality, such as AR glasses and the like, are currently on the market.

As shown in fig. 1, the conventional display optical machine 10P generally includes an image source unit 11P, a half-reflective and half-transmissive mirror 12P and a curved reflective mirror 13P, and image light emitted by the image source unit 11P is reflected to human eyes through the half-reflective and half-transmissive mirror 12P and the curved reflective mirror 13P. Generally, the curved reflector 13P is a partial reflector, that is, a part of light is reflected and transmitted according to a certain ratio (for example, 50% of light is reflected and 50% of light is transmitted), so that the curved reflector 13P not only can reflect a part of image light back to the human eye to make the human see the corresponding image, but also can allow light of the real environment to penetrate through the curved reflector 13P to enter the human eye to make the human see the real environment, thereby achieving the purpose of augmented reality.

However, only half of the image light emitted from the image source unit 11P is reflected by the half mirror 12P to the curved mirror 13P, and the other half of the image light escapes through the half mirror 12P; then, the curved reflector 13P can only reflect approximately half of the image light to the half-reflective half-transparent mirror 12P, and the other half of the image light escapes through the curved reflector 13P; finally, only half of the image light reflected by the curved reflector 13P can pass through the transflective mirror 12P to reach the human eye, and the other half of the image light escapes due to the reflection of the transflective mirror 12P. In other words, only 1/8 light rays of the image light rays emitted by the image source unit 11P can be incident to the human eyes, and the rest 7/8 light rays are wasted, that is, the light utilization efficiency of the image light rays of the existing display light machine 10P is extremely low, only about 12.5%, which results in insufficient intensity of the image light rays reaching the human eyes, so that the contrast of the enhanced display image is seriously reduced by the ambient light rays or the interference light rays entering the human eyes, thereby reducing the enhanced display experience of the user. Therefore, a new display light machine is urgently needed to solve the problems.

Disclosure of Invention

An object of the present invention is to provide a near-eye display optical device, a method thereof, and a near-eye display apparatus, which can improve the light energy utilization rate of the image light of the near-eye display optical device.

Another object of the present invention is to provide a near-eye display optical engine, a method thereof and a near-eye display device, which are helpful to adapt to the trend of light weight, thinness and miniaturization of the near-eye display device.

Another object of the present invention is to provide a near-eye display optical engine, a method thereof and a near-eye display device, wherein, in an embodiment of the present invention, an included angle between a polarization beam splitting component of the near-eye display optical engine and an optical viewing axis is in a range of 50 ° to 70 °, which is helpful for improving the overall compactness of the near-eye display optical engine.

Another object of the present invention is to provide a near-eye display optical machine, a method thereof and a near-eye display device, wherein in an embodiment of the present invention, the near-eye display optical machine utilizes characteristics of polarized light to reduce light energy loss of image light through a reasonable optical design, thereby improving light energy utilization of the image light.

Another object of the present invention is to provide a near-eye display optical engine, a method thereof and a near-eye display device, wherein in an embodiment of the present invention, the near-eye display optical engine can reduce the amount of image light escaping, reduce the image leakage displayed, not only contribute to further improving the light energy utilization rate of the image light, but also contribute to protecting the privacy of a user.

Another object of the present invention is to provide a near-eye display optical engine, a method thereof, and a near-eye display device, wherein in an embodiment of the present invention, an anti-interference unit of the near-eye display optical engine employs a linear polarizer to eliminate artifact interference caused by ambient light below, which is helpful for improving a comfortable experience of a user.

Another object of the present invention is to provide a near-eye display optical engine, a method thereof and a near-eye display device, wherein in an embodiment of the present invention, an anti-interference unit of the near-eye display optical engine has a simple structure, a low cost and a good artifact removing effect.

Another object of the present invention is to provide a near-eye display light engine, a method thereof, and a near-eye display device, wherein in order to achieve the above object, it is not necessary to use expensive materials or complicated structures in the present invention. Therefore, the present invention successfully and effectively provides a solution to not only provide a near-eye display optical engine and method thereof and a near-eye display device, but also increase the practicality and reliability of the near-eye display optical engine and method thereof and the near-eye display device.

To achieve at least one of the above objects or other objects and advantages, the present invention provides a near-eye display light engine, comprising:

an image source unit for emitting image light along an emission path;

a lens assembly unit, wherein the lens assembly unit is arranged on the emission path of the image source unit and is used for modulating the image light emitted by the image source;

a polarization beam splitting unit, wherein the polarization beam splitting unit is disposed in the emission path of the image source unit, and the lens assembly unit is disposed between the image source unit and the polarization beam splitting unit, wherein an included angle between the polarization beam splitting unit and an optical viewing axis of the near-eye display optical machine is greater than 45 °, and the polarization beam splitting unit is configured to reflect a first polarized image light of the image lights modulated by the lens assembly unit and transmit a second polarized image light of the image lights modulated by the lens assembly unit;

a perspective reflection unit, wherein the perspective reflection unit is disposed on a reflection side of the polarization beam splitting unit, and the perspective reflection unit corresponds to the optical viewing axis of the near-eye display optical machine, and is configured to reflect a part or all of the first polarized image light reflected by the polarization beam splitting unit back to the polarization beam splitting unit, and allow a part of ambient light to pass through; and

and the polarization conversion unit is arranged between the polarization light splitting unit and the perspective reflection unit and is used for converting the first polarization image light into the second polarization image light after the first polarization image light passes through the second polarization image light twice and then transmitting the polarization light splitting unit to be incident into human eyes.

In an embodiment of the invention, an angle between the polarization beam splitting unit and the optical viewing axis of the near-eye display optical machine is between 50 ° and 70 °.

In an embodiment of the invention, the polarization beam splitting unit includes a light-transmitting substrate and a polarization beam splitting film, wherein the polarization beam splitting film is disposed on the first optical surface of the light-transmitting substrate, and the polarization beam splitting film is located between the light-transmitting substrate and the image source unit.

In an embodiment of the invention, the surface of the first optical surface of the light-transmitting substrate is a free-form surface.

In an embodiment of the invention, the transillumination reflection unit includes a curved substrate and a partially reflective film, wherein the partially reflective film is disposed on the second optical surface of the curved substrate, and the partially reflective film is disposed between the curved substrate and the polarization splitting unit.

In an embodiment of the invention, the second optical surface of the curved substrate has a free-form surface.

In an embodiment of the present invention, the near-eye display optical machine further includes an anti-interference unit, wherein the anti-interference unit is located on a side of the polarization beam splitting unit 12 away from the image source unit, and is used for preventing the interference light from below from generating visual interference.

In an embodiment of the invention, the anti-interference unit includes a polarization filter element, wherein the polarization filter element is disposed on a side of the polarization beam splitting unit away from the image source unit, and is configured to absorb a first polarized light and transmit a second polarized light, wherein a polarization state of the first polarized light and a polarization state of the first polarized image light are consistent, and a polarization state of the second polarized light and a polarization state of the second polarized image light are consistent.

In an embodiment of the invention, the polarization filter element is a linear polarizer.

In an embodiment of the invention, the anti-interference unit further includes a protective substrate and an anti-reflection film, wherein the protective substrate is located outside the polarized light filtering element, so that the polarized light filtering element is located between the protective substrate and the polarization splitting unit, and the anti-reflection film is disposed on an outer surface of the protective substrate.

In an embodiment of the present invention, the polarization conversion unit is an 1/4 wave plate.

In an embodiment of the present invention, the lens group unit includes at least one lens, wherein each lens has one of a standard spherical surface, an aspherical surface, a free-form surface and a diffractive surface.

In an embodiment of the present invention, the image source unit is one of an LCD type, an OLED type, a DLP type and an LCOS type micro display device.

According to another aspect of the present invention, there is also provided a near-eye display device comprising:

an apparatus main body; and

at least one near-eye display optical machine of any one of the above, wherein the near-eye display optical machine is disposed in the device main body to assemble a compact near-eye display device.

According to another aspect of the present invention, the present invention further provides a method for manufacturing a near-eye display optical machine, including the steps of:

arranging a lens group unit between an image source unit and a polarization beam splitting unit, wherein the lens group unit and the polarization beam splitting unit are both positioned on an emission path of the image source unit, the lens group unit is used for modulating the image light emitted by the image source, and the polarization beam splitting unit is used for reflecting a first polarization image light in the modulated image light and transmitting a second polarization image light in the modulated image light;

arranging a perspective reflection unit on the reflection side of the polarization beam splitting unit to define an optical viewing axis through the perspective reflection unit and the polarization beam splitting unit, wherein an included angle between the polarization beam splitting unit and the optical viewing axis is greater than 45 degrees, and the perspective reflection unit is used for reflecting part or all of the first polarization image light reflected by the polarization beam splitting unit back to the polarization beam splitting unit and allowing part of ambient light to transmit; and

and arranging a polarization conversion unit between the polarization beam splitting unit and the perspective reflection unit, wherein the polarization conversion unit is used for converting the first polarization image light into the second polarization image light after passing through the polarization conversion unit twice, and then the second polarization image light is incident into human eyes along the optical viewing axis.

In an embodiment of the present invention, the method for manufacturing a near-eye display optical machine further includes:

arranging an anti-interference unit on one side of the polarization light splitting unit far away from the image source unit, wherein the anti-interference unit comprises a polarization filtering element used for absorbing first polarized light and transmitting second polarized light, and the polarization state of the first polarized light is consistent with that of the first polarized image light; and the polarization state of the second polarized light is consistent with the polarization state of the second polarized image light.

Further objects and advantages of the invention will be fully apparent from the ensuing description and drawings.

These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, the accompanying drawings and the claims.

Drawings

Fig. 1 shows a schematic structural diagram of a display light machine in the prior art.

Fig. 2 is a schematic structural diagram of a near-eye display optical machine according to a first embodiment of the present invention.

Fig. 3 is a schematic optical path diagram of the near-eye display optical machine according to the first embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a near-eye display optical machine according to a second embodiment of the present invention.

Fig. 5 is a partially enlarged schematic view of the near-eye display optical machine according to the second embodiment of the present invention.

Fig. 6 illustrates one example of a near-eye display device according to an embodiment of the present invention.

Fig. 7 is a flowchart illustrating a method for manufacturing a near-eye display optical engine according to an embodiment of the invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be constructed and operated in a particular orientation and thus are not to be considered limiting.

In the present invention, the terms "a" and "an" in the claims and the description should be understood as meaning "one or more", that is, one element may be one in number in one embodiment, and the element may be more than one in number in another embodiment. The terms "a" and "an" should not be construed as limiting the number unless the number of such elements is explicitly recited as one in the present disclosure, but rather the terms "a" and "an" should not be construed as being limited to only one of the number.

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

In recent years, with the rapid development of augmented reality technology, near-eye display devices capable of realizing augmented reality are becoming more popular and used by people. However, the conventional display optical device has a very low light energy utilization ratio (usually about 12.5%) for image light, and the size of the conventional display optical device is too large, which not only causes poor image quality of the conventional display optical device, but also does not meet the development trend of miniaturization and lightness of the existing head-mounted display device.

In order to solve the above problems, referring to fig. 2 and fig. 3, a first embodiment of the present invention provides a new near-eye display optical engine, which not only can greatly improve the light energy utilization rate of image light, but also can help make the structure of the near-eye display optical engine compact. Specifically, as shown in fig. 2, the near-eye display optical machine 10 includes an image source unit 11, a polarization beam splitting unit 12, a perspective reflection unit 13, a polarization conversion unit 14, and a lens assembly unit 15.

The image source unit 11 has an emission path 110 for emitting image light 1100 along the emission path 110. The lens group unit 15 is disposed on the emission path 110 of the image source unit 11, and is used for modulating the image light 1100 emitted through the image source unit 11.

The polarization beam splitting unit 12 is disposed on the emission path 110 of the image source 11, and is configured to reflect a first polarized image light 1101 and transmit a second polarized image light 1102. The polarization beam splitting unit 12 and the image source unit 11 are respectively located at two sides of the lens assembly unit 15 (i.e. the lens assembly unit 15 is located between the polarization beam splitting unit 12 and the image source unit 11), and an included angle θ between the polarization beam splitting unit 12 and the optical viewing axis 100 of the near-eye display optical machine 10 is greater than 45 °, so that the polarization beam splitting unit 12 is configured to reflect the first polarized image light 1101 of the image light 1100 modulated by the lens assembly unit 15, and transmit the second polarized image light 1102 of the image light 1100 modulated by the lens assembly unit 15.

The see-through reflection unit 13 is disposed on a reflection side of the polarization beam splitting unit 12, and the see-through reflection unit 13 corresponds to the optical viewing axis 100 of the near-eye display optical engine 10, and is configured to reflect a part or all of the first polarized image light 1101 reflected by the polarization beam splitting unit 12 back to the polarization beam splitting unit 12, and allow a part of ambient light to transmit to the polarization beam splitting unit 12. The polarization conversion unit 14 is disposed between the polarization beam splitting unit 12 and the perspective reflection unit 13, and is configured to convert the first polarized image light 1101 into the second polarized image light 1102 after passing through the polarization conversion unit 14 twice.

Like this, via the second deflection image light 1102 that polarization conversion unit 14 converted into with see through the ambient light of perspective reflection unit 13 will see through earlier polarization beam splitting unit 12, reentrant to people's eye in and observed for the user can see simultaneously with the help of near-to-eye display light machine 10 with the virtual image that image light 1100 corresponds and with the real image that ambient light corresponds to realize augmented reality's experience. It can be understood that the optical viewing axis 100 of the near-eye display optical machine 10 may be a main viewing axis defined by the polarization beam splitting unit 12 and the perspective reflection unit 13, so that a user can see both the image light emitted by the image source unit 11 and the external ambient light along the optical viewing axis 100 to obtain a virtual-real fused augmented reality experience. It is understood that the perspective reflection unit 13 can be optimally adjusted according to the specific system design.

In other words, since the second deflected image light 1102 converted by the polarization conversion unit 14 can pass through the polarization splitting unit 12, no loss occurs due to reflection of the polarization splitting unit 12, which is helpful for improving the light energy utilization efficiency of the near-eye display light engine 10 for image light. For example, when the perspective reflection unit 13 of the near-eye display optical machine 10 is a partial reflector (i.e., reflects 50% of light and transmits 50% of light), image light is only half lost when reaching the polarization beam splitting unit 12 for the first time and passing through the perspective reflection unit 13, respectively, that is, the optical energy utilization rate of the near-eye display optical machine 10 for image light reaches 25%, which is twice higher than the optical energy utilization rate of the existing display optical machine 10P for image light. Meanwhile, since the included angle θ between the polarization beam splitting unit 12 and the optical viewing axis 100 of the near-eye display optical machine 10 is greater than 45 °, an eye-relief (i.e. an eye-point distance, such as a distance from a lens to a forehead) of the near-eye display optical machine 10 is increased, so that an adapter is added for a near-sighted or far-sighted user, and the wearing experience and comfort of the user are improved. In addition, this configuration also helps to make the near-eye display light engine 10 more compact in size than the existing light engine by design adjustment of the whole system, and is suitable for meeting the current trend of miniaturization and lightness.

Preferably, as shown in FIG. 3, the angle θ between the polarizing beam splitting unit 12 and the optical viewing axis 100 of the near-eye display light engine 10 is between 50 ° and 70 °, i.e., 50 ° ≦ θ ≦ 70 °.

It is noted that, in the present invention, the first polarized image light 1101 can be implemented as polarized light having a first polarization state, and the second polarized image light 1102 can be implemented as polarized light having a second polarization state, wherein the polarization direction of the first polarized image light 1101 is preferably perpendicular to the polarization direction of the second polarized image light 1102. For example, the first polarized image light 1101 may be implemented as, but not limited to, S-polarized light or P-polarized light, and the second polarized image light 1102 may be implemented as, but not limited to, P-polarized light or S-polarized light, respectively.

Furthermore, in this first embodiment of the present invention, as shown in fig. 2 and 3, the polarization conversion unit 14 may be, but is not limited to, implemented as a first 1/4 waveplate 141 for converting the first or second polarized image light 1101, 1102 that twice passes through the 1/4 waveplate 141 into the second or first polarized image light 1102, 1101. That is, the first 1/4 wave plate 141 is disposed between the polarization splitting unit 12 and the transflective unit 13, the first polarized image light 1101 thus reflected by the polarization beam splitting unit 12 first passes through the first 1/4 waveplate 141 to be converted into first circularly polarized light, after being reflected by the transflective unit 13 to be converted into the second circularly polarized light, it passes through the first 1/4 waveplate 141 a second time to be converted into the second polarized image light 1102, such that the first polarized image light ray 1101 is converted to the second polarized image light ray 1102 after passing twice through the 1/4 waveplate 141, therefore, most of the reflected image light can pass through the polarization splitting unit 12 to be incident to human eyes, which is helpful for improving the light energy utilization rate of the near-eye display light engine 10 for the image light.

It is worth mentioning that, as shown in fig. 3, the polarization splitting unit 12 of the near-eye display optical machine 10 according to the first embodiment of the present invention may include a transparent substrate 121 and a polarization splitting film 122, wherein the transparent substrate 121 has a first optical surface 120, and the first optical surface 120 of the transparent substrate 121 faces the image source unit 11 (i.e. the first optical surface 120 is the upper surface of the transparent substrate 121), wherein the polarization splitting film 122 is disposed on the first optical surface 120 of the transparent substrate 121, so that the polarization splitting film 122 is located between the transparent substrate 121 and the image source unit 11 for reflecting the first polarized image light 1101 in the image light 1100.

In particular, the polarization splitting film 122 may be, but is not limited to, attached or plated to the first optical surface 120 of the light-transmitting substrate 121. It is understood that the light transmissive substrate 121 may be made of, but not limited to, a light transmissive material such as optical plastic or optical glass, etc., to ensure that light can transmit through the light transmissive substrate 121.

Preferably, the surface shape of the first optical surface 120 of the light-transmitting substrate 121 of the polarization beam splitting unit 12 may be, but is not limited to, implemented as a free-form surface, so that image light or ambient light can be shaped when reflected or transmitted at the polarization beam splitting unit 12, which helps to improve the imaging quality of the near-eye display light engine 10.

Similarly, as shown in fig. 3, the see-through reflection unit 13 of the near-eye display optical device 10 according to the first embodiment of the present invention may include a curved substrate 131 and a partial reflection film 132, wherein the curved substrate 131 has a second optical surface 130, and the second optical surface 130 of the curved substrate 131 faces the polarization splitting unit 12 (i.e. the second optical surface 130 is an inner surface of the curved substrate 131), wherein the partially reflective film 132 is disposed on the second optical surface 130 of the curved substrate 131, such that the partially reflective film 132 is positioned between the polarization splitting unit 12 and the curved substrate 131, for reflecting the first polarized image light rays 1101 such that the first polarized image light rays 1101 are converted to the second polarized image light rays 1102 by passing twice through the first 1/4 waveplate 141.

In particular, the partially reflective film 132 may be, but is not limited to, attached or plated to the second optical surface 130 of the curved substrate 131. It is understood that the curved substrate 131 may be made of a light-transmissive material such as optical plastic or optical glass, etc. to ensure that ambient light can pass through the see-through reflection unit 13.

Preferably, the surface type of the second optical surface 130 of the curved substrate 131 of the transreflective unit 13 may also be, but is not limited to, implemented as a free-form surface, so that image light and ambient light can be shaped while being reflected or transmitted at the second optical surface 130 of the transreflective unit 13.

It should be noted that in other examples of the present invention, the first optical surface 130 of the curved substrate 131 may also face the opposite direction of the polarization beam splitting unit 12 (i.e., the second optical surface 130 is the outer surface of the curved substrate 131), so that the curved substrate 131 is located between the partially reflective film 132 and the polarization beam splitting unit 12, and thus the image light will first transmit through the curved substrate 131 and then be emitted by the partially reflective film 132 to transmit through the curved substrate 131 again to the polarization beam splitting unit 12.

According to the first embodiment of the present invention, as shown in fig. 2 and 3, the lens assembly unit 15 of the near-eye display optical machine 10 may include, but is not limited to, at least one lens 151, wherein the surface shape of each lens 151 may be, but is not limited to, implemented as, for example, a standard spherical surface, an aspherical surface, a free-form surface or a diffractive surface, and is used for performing modulation shaping on the image light 1100 from the image source unit 11. In other words, the surface type of the at least one lens 151 may be, but is not limited to, one or more selected from the group consisting of a standard spherical surface, an aspherical surface, a free-form surface, and a diffractive surface. It is understood that the free-form surface mentioned in the present invention may be, but is not limited to, a surface type implemented as an XY polynomial free-form surface, a Zernike polynomial free-form surface, or a toric surface, etc.

It is worth mentioning that in the above-mentioned first embodiment of the present invention, the image source unit 11 can be, but is not limited to be, implemented as one of LCD, OLED, DLP, LCOS type micro display devices for providing the image light 1100. Particularly, when the image source unit 11 is implemented as an LCOS type micro display device, the LCOS type micro display device can emit image light with a specific polarization state so as to be matched with the polarization splitting unit 12, so that the image light emitted by the image source unit 11 is not lost at the polarization splitting unit 12, which is helpful for further improving the light energy utilization rate of the near-eye display light machine 10 for the image light.

It can be understood that the image source unit 11 of the near-eye display optical engine 10 is implemented as an LCOS type micro display device for emitting the first polarized image light 1101 along the emission path 110, so that most of the first polarized image light 1101 emitted by the LCOS type micro display device is reflected by the polarization splitting unit 12 to the see-through reflection unit 13 without loss due to transmission through the polarization splitting unit 12, so that the optical energy utilization rate of the near-eye display optical engine 10 for the image light can be greatly improved. In other words, the image light is only lost due to transmission at the perspective reflection unit 13, and is not lost due to reflection or transmission at the polarization splitting unit 12, so that the light energy utilization rate of the near-eye display light engine 10 for the image light is close to 50%.

However, since the image light is transmitted at the perspective reflection unit 13, that is, the image light escapes from the front of the near-eye display optical engine 10, this not only causes the light energy loss of the image light, but also causes the light energy utilization rate of the near-eye display optical engine 10 for the image light to be low, and thus a high-quality image cannot be provided; but also enables others to see the image the user is watching from the outside of the near-eye display light machine 10, and the privacy of the user cannot be protected.

Therefore, in order to solve these problems, some embodiments of the present invention provide a near-eye display optical machine, where the image source unit of the near-eye display optical machine is configured to emit image light with a predetermined spectrum, and the perspective reflection unit of the near-eye display optical machine includes a reflection film system configured to reflect the predetermined spectrum, so as to greatly reduce the escape of the image light from the front of the near-eye display optical machine, so that the image displayed by the near-eye display optical machine cannot be seen by the outside, thereby achieving the purposes of improving the light energy utilization rate and protecting privacy.

It should be noted that, in the embodiments of the present invention, the detailed description and various modifications of the perspective reflection unit of the near-eye display optical machine can refer to the chinese patent with patent application No. 201811523682.9, entitled "a display optical machine and a manufacturing method thereof and a near-eye display device" that have been applied by the present applicant, and the present invention is not repeated herein.

It should be noted that, limited by the self structure of the near-eye display optical machine 10 according to the first embodiment of the present invention, the ambient light (hereinafter referred to as interference light) below the near-eye display optical machine 10 will inevitably be reflected into human eyes by the polarization splitting unit 12, so that a user can see a virtual image of an object below the near-eye display optical machine 10 while watching a scene in front of the near-eye display optical machine 10, thereby causing visual interference (i.e., artifact interference). Therefore, in order to solve the above problem, as shown in fig. 4 and 5, a second embodiment of the present invention provides a near-eye display optical engine 10A, which can effectively prevent the lower disturbing light from being reflected to the eyes of the user to prevent the occurrence of visual disturbance. Specifically, as shown in fig. 4, the near-eye display light engine 10A according to the second embodiment of the present invention is different from the above-described first embodiment of the present invention in that: the near-eye display optical machine 10A further includes an anti-interference unit 16A, wherein the anti-interference unit 16A is located on a side of the polarization beam splitting unit 12 away from the image source unit 11, and is configured to prevent the interference light 100A from below the near-eye display optical machine 10A from generating visual interference.

More specifically, as shown in fig. 4 and 5, the interference preventing unit 16A includes a polarization filter element 161A, wherein the polarization filter element 161A is disposed on a side of the polarization splitting unit 12 away from the image source unit 11, and is configured to absorb the first polarized light 101A and transmit the second polarized light 102A, wherein the first polarized light 101A is implemented as polarized light having a first polarization state, and the second polarized light 102A is implemented as polarized light having a second polarization state. In other words, in the present invention, the polarization state of the first polarized light 101A is consistent with the polarization state of the first polarized image light 1101; and the polarization state of the second polarized light 102A is consistent with the polarization state of the second polarized image light 1102 (e.g. the first polarized light 101A and the first polarized image light 1101 have the same polarization state, and the second polarized light 102A and the second polarized image light 1102 have the same polarization state). For example, in one example of the present invention, the first polarized light 101A and the first polarized image light 1101 are each implemented as polarized light having an S-polarized state (S-polarized light for short); the second polarized light 102A and the second polarized image light 1102 are each implemented as polarized light having a P polarization state (P polarized light for short).

Therefore, when the disturbance light from below the near-eye display light engine 10A passes through the polarized light filter element 161A of the disturbance prevention unit 16A, first, the first polarized light 101A in the disturbance light 100A is absorbed by the polarized light filter element 161A, and the second polarized light 102A in the disturbance light 100A is transmitted, so that the disturbance light 100A is filtered into the second polarized light 102A by unpolarized light; next, the second polarized light 102A transmitted through the polarized light filter element 161A is transmitted upward to the polarization splitting unit 12 to transmit through the polarization splitting unit 12 and escape, without being reflected to human eyes, so as to achieve the purpose of preventing the disturbing light 100A from the lower side of the near-eye display light engine 10A from generating visual interference.

It is understood that, since the polarization splitting unit 12 is configured to reflect the polarized light having the first polarization state and transmit the polarized light having the second polarization state, the second polarized light 102A transmitted through the polarization filter element 161A only transmits through the polarization splitting unit 12, and is not reflected by the polarization splitting unit 12. In addition, since the polarized light filter element 161A allows the second polarized light 102A to pass through, that is, the polarized light with the second polarization state to pass through, after the image light and the ambient light propagating along the optical viewing axis pass through the polarization splitting unit 12, they can necessarily pass through the polarized light filter element 161A to propagate to the human eye, so that the anti-interference unit 16A plays a role of eliminating the artifact, and at the same time, does not affect the original effect (such as image contrast, light energy utilization rate, etc.) of the near-eye display light engine 10A, which is helpful to greatly improve the comfortable experience of the user.

Exemplarily, in this embodiment of the present invention, the polarization filter element 161A may be, but is not limited to be, implemented as a linear polarizer for allowing only the second polarized light to pass therethrough and absorbing the first polarized light. Preferably, the polarization filter element 161A is implemented as a P-polarizer for allowing only P-polarized light to pass therethrough and absorbing S-polarized light so as to match the polarization splitting film (e.g., PBS film, reflecting S-polarized light, and transmitting P-polarized light) in the polarization splitting unit 12.

Further, as shown in fig. 5, the interference preventing unit 16A may further include a protective substrate 162A, wherein the protective substrate 162A is located outside the polarization filter element 161A, so that the polarization filter element 161A is located between the protective substrate 162A and the polarization splitting unit 12, so as to protect and support the polarization filter element 161A by the protective substrate 162A. It is understood that the protective substrate 162A may be made of, but not limited to, a light-transmitting material such as glass, transparent plastic, etc. to allow light to transmit through the protective substrate 162A.

Preferably, as shown in fig. 5, the anti-interference unit 16A may further include an anti-reflection film 163A, wherein the anti-reflection film 163A is disposed on the outer surface of the protection substrate 162A, and is used for reducing reflection of the interference light 100A on the outer surface of the protection substrate 162A, which helps to avoid causing visual interference. It is understood that the antireflection film 163A may be, but is not limited to, plated on the outer surface of the protective substrate 162A. For example, in other examples of the present invention, the antireflection film 163A may be directly attached to the outer surface of the protective substrate 162A.

It is to be noted that, in the second embodiment of the present invention, except for the above-mentioned differences, other structures of the near-eye display optical engine 10A are the same as those of the near-eye display optical engine 10 according to the first embodiment of the present invention, and the near-eye display optical engine 10A also has similar or identical modified embodiments to those of the near-eye display optical engine 10 according to the first embodiment, and therefore, no further description is provided herein.

According to another aspect of the invention, the invention further provides a near-eye display device configured with a near-eye display light engine. Illustratively, as shown in fig. 6, the near-eye display device 1 may include at least one near-eye display light engine 10(10A) and a device body 20, wherein the near-eye display light engine 10(10A) is disposed on the device body 20 to assemble the near-eye display device 1 in a compact structure, so that the near-eye display device has a smaller volume and lighter weight, and is helpful to meet the current trend of miniaturization and lightness.

It is noted that the device body 20 may be, but is not limited to be, implemented as a glasses body, such that the near-eye display device 1 is implemented as AR glasses, contributing to the user's use experience. It will be appreciated that in other examples of the invention, the near-eye display device 1 may also be implemented as other types of AR devices, such as an AR helmet or the like.

According to another aspect of the present invention, the present invention further provides a method for manufacturing a near-eye display optical machine. Specifically, as shown in fig. 7, the method for manufacturing the near-eye display optical engine 10 includes the steps of:

s310: disposing a lens assembly unit 15 between an image source unit 11 and a polarization beam splitting unit 12, and the lens assembly unit 15 and the polarization beam splitting unit 12 are both located in an emission path of the image source unit 11, wherein the lens assembly unit 15 is configured to modulate the image light 1100 emitted from the image source unit 11, and wherein the polarization beam splitting unit 12 is configured to reflect a first polarized image light 1101 of the modulated image light 1100 and transmit a second polarized image light 1102 of the modulated image light 1100;

s320: disposing a perspective reflection unit 13 on a reflection side of the polarization beam splitting unit 12 to define an optical viewing axis 100 through the perspective reflection unit 13 and the polarization beam splitting unit 12, wherein an included angle between the polarization beam splitting unit 12 and the optical viewing axis 100 is greater than 45 °, wherein the perspective reflection unit 13 is configured to reflect a part or all of the first polarized image light 1101 reflected by the polarization beam splitting unit 12 back to the polarization beam splitting unit 12, and allow a part of ambient light to pass through to propagate to the polarization beam splitting unit 12; and

s330: a polarization conversion unit 14 is disposed between the polarization beam splitting unit 12 and the perspective reflection unit 13, and is configured to convert the first polarized image light 1101 into the second polarized image light 1102 after passing through the polarization conversion unit 14 twice, and then enter the human eye along the optical viewing axis 100 to be viewed.

It is understood that, in the method for manufacturing the near-eye display optical engine 10 of the present invention, the sequence of the step S310, the step S320, and the step S330 is not sequential.

It is noted that in an example of the present invention, the polarization splitting unit 12 includes a transparent substrate 121 and a polarization splitting film 122, wherein the polarization splitting film 122 is disposed on the first optical surface 120 of the transparent substrate 121, and the polarization splitting film 122 is disposed between the transparent substrate 121 and the image source unit 11.

In one example of the present invention, the surface shape of the first optical surface of the light-transmitting substrate is a free-form surface.

In an example of the present invention, the transreflective unit 13 includes a curved substrate 131 and a partially reflective film 132, wherein the partially reflective film 132 is disposed on the second optical surface 130 of the curved substrate 131 for reflecting the first polarized image light 1101 such that the first polarized image light 1101 passes through the first 1/4 waveplate 141 twice to be converted into the second polarized image light 1102.

In one example of the present invention, the second optical surface of the curved substrate has a free-form surface.

It should be noted that, as shown in fig. 7, the method for manufacturing the near-eye display optical engine 10 may further include the steps of:

s340: disposing an anti-interference unit 16A on a side of the polarization splitting unit 12 away from the image source unit 11, wherein the anti-interference unit 16A includes a polarization filter element 161A for absorbing a first polarized light 101A and transmitting a second polarized light 102A, and a polarization state of the first polarized light 101A is consistent with a polarization state of the first polarized image light 1101; and the polarization state of the second polarized light 102A is consistent with the polarization state of the second polarized image light 1102.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.

Claims

1. A near-eye display light engine, comprising:

an image source unit for emitting image light along an emission path;

2. The near-eye display light engine of claim 1, wherein an angle between the polarization beam splitting unit and the optical viewing axis of the near-eye display light engine is between 50 ° and 70 °.

3. The near-eye display light engine of claim 2, wherein the polarization splitting unit comprises a light transmissive substrate and a polarization splitting film, wherein the polarization splitting film is disposed on the first optical surface of the light transmissive substrate and the polarization splitting film is between the light transmissive substrate and the image source unit.

4. The near-eye display light engine of claim 3, wherein the face shape of the first optical face of the light transmissive substrate is a free-form surface.

5. The near-eye display light engine of any one of claims 1 to 4, wherein the see-through reflection unit comprises a curved substrate and a partially reflective film, wherein the partially reflective film is disposed on the second optical surface of the curved substrate, and the partially reflective film is disposed between the curved substrate and the polarization splitting unit.

6. The near-eye display light engine of claim 5, wherein the second optical surface of the curved substrate is free-form.

7. The near-eye display light machine of any one of claims 1 to 4, further comprising an anti-interference unit, wherein the anti-interference unit is located on a side of the polarization beam splitting unit 12 away from the image source unit for preventing the interference light from below from generating visual interference.

8. The near-eye display light engine of claim 7, wherein the anti-interference unit comprises a polarization filter element, wherein the polarization filter element is disposed on a side of the polarization beam splitting unit away from the image source unit, and is configured to absorb a first polarization and transmit a second polarization, wherein a polarization state of the first polarization and a polarization state of the first polarization image light are consistent, and a polarization state of the second polarization image light are consistent.

9. The near-eye display light engine of claim 8, wherein the polarizing filter element is a linear polarizer.

10. The near-eye display light engine of claim 9, wherein the interference prevention unit further comprises a protective substrate and an antireflection film, wherein the protective substrate is located outside the polarization filter element so that the polarization filter element is located between the protective substrate and the polarization splitting unit, and wherein the antireflection film is disposed on an outer surface of the protective substrate.

11. The near-eye display light engine of any one of claims 1 to 4, wherein the polarization conversion unit is an 1/4 wave plate.

12. The near-eye display light engine of any one of claims 1 to 4, wherein the lens assembly unit comprises at least one lens, wherein each lens has one of a standard spherical surface, an aspherical surface, a free-form surface and a diffractive surface.

13. The near-eye display light engine of any one of claims 1 to 4, wherein the image source unit is one of an LCD type, an OLED type, a DLP type, and an LCOS type micro display device.

14. A near-eye display device, comprising:

an apparatus main body; and

the near-eye display engine of any one of claims 1-13, wherein the near-eye display engine is disposed in the device body to assemble a compact near-eye display device.

15. A method for manufacturing a near-eye display optical machine is characterized by comprising the following steps:

16. The method of manufacturing the near-eye display light engine of claim 15, further comprising the steps of: