CN117170166A

CN117170166A - Miniature projection module and head-mounted display equipment

Info

Publication number: CN117170166A
Application number: CN202210589708.XA
Authority: CN
Inventors: 刘冰玉; 杜佳玮; 李潍; 李泓
Original assignee: Ningbo Sunny Opotech Co Ltd
Current assignee: Ningbo Sunny Opotech Co Ltd
Priority date: 2022-05-26
Filing date: 2022-05-26
Publication date: 2023-12-05
Also published as: WO2023226711A1

Abstract

The application provides a miniature projection module and head-mounted display equipment comprising the miniature projection module. The miniature projection module comprises: an illumination assembly configured to provide polarized illumination light; and a display chip configured to modulate the polarized illumination light into polarized image light; and a relay assembly configured to transmit the polarized illumination light to the display chip and the polarized image light to the projection assembly, the relay assembly including a polarization beam splitting assembly; and the projection assembly is configured to project and image the polarized image light and comprises a first projection sub-lens and a second projection sub-lens, wherein the first projection sub-lens is arranged in a light path between the polarization beam splitting assembly and the display chip, the second projection sub-lens and the first projection sub-lens are arranged on two opposite sides of the polarization beam splitting assembly, and the optical axes of the second projection sub-lens and the first projection sub-lens are positioned on the same straight line.

Description

Miniature projection module and head-mounted display equipment

Technical Field

The application relates to the technical field of optical imaging, in particular to a miniature projection module and a head-mounted display device comprising the miniature projection module.

Background

The augmented reality (Augmented Reality, abbreviated as AR) technology is a new technology for integrating real world information and virtual world information in a seamless way, and is characterized in that entity information which is difficult to experience in a certain time space range of the real world originally is overlapped after simulation and emulation by using scientific technologies such as a computer, so that people obtain sensory experience exceeding reality. The augmented reality technology has a huge application potential in a plurality of fields due to the characteristic of superposing virtual objects or pictures in a real environment.

The imaging quality and the size of the projection module, namely the optical machine, which is used as a key device in the augmented reality technology directly determine the quality of user experience, and how to balance between the good imaging quality and the small size is always one of the important points of attention of various manufacturers.

In recent years, with the development of micro display chip technology, the main micro projection display chip currently has a TFT-LCD, LCoS, DMD and a micro LED chip. The single-color micro LED optical machine becomes a pet in the market by virtue of the light property. However, because of the large application limitation of the single-color AR product, the consumers who are used to gorgeous pictures cannot meet the expectations of the AR product, and the full-color AR product is still an industry trend. The micro led chip is limited by the bottleneck of material technology and quantum dot conversion technology, and the problem of the luminous efficiency of the red chip cannot be solved in a short period, so that the full-color AR light machine based on the micro led chip cannot fall to the ground, and the RGB full-color micro led chip cannot push out products in a short period. The TFT-LCD chip has the disadvantages of lower contrast ratio, low light energy utilization rate, lower brightness and lower resolution, and the optimal technical scheme of the full-color AR product can only select LCoS or DLP scheme based on the DMD chip at present. DMD chips are slightly superior to LCoS chips in terms of resolution, brightness, contrast, and light energy utilization. However, since DMD chips are globally unique, more mass-production suppliers of LCoS chips choose from, and therefore, cost-effective LCoS optomachines have significant advantages.

The existing LCoS light machine generally sets an illumination system and a projection system at two sides of a PBS prism, and is limited by an optical focal length, the illumination system, the relay system and the projection system have limit lengths, the light machine is integrally in a linear structure, the volume is difficult to reduce, and the trend of miniaturization and light weight of near-eye display equipment can not be met, so that a small-size and light miniature projection module and a head-mounted display device matched with the miniature projection module are required to meet market demands.

Disclosure of Invention

The application aims to provide a miniature projection module and a head-mounted display device, which can meet the market trend of miniaturization and light weight.

In order to achieve the above object, according to a first aspect of the present application, there is provided a micro-projection module, comprising:

an illumination assembly configured to provide polarized illumination light; the method comprises the steps of,

a display chip configured to modulate the polarized illumination light into polarized image light; and

a relay assembly configured to transmit the polarized illumination light to the display chip and the polarized image light to the projection assembly, the relay assembly comprising a polarization beam splitting assembly; and

the projection assembly is configured to project and image the polarized image light and comprises a first projection sub-lens and a second projection sub-lens, wherein the first projection sub-lens is arranged in an optical path between the polarized light splitting assembly and the display chip and is configured to provide a transmission path for the polarized illumination light and the polarized image light and perform optical path correction, the second projection sub-lens and the first projection sub-lens are arranged on two opposite sides of the polarized light splitting assembly, and the second projection sub-lens and an optical axis of the first projection sub-lens are positioned on the same straight line.

According to an embodiment of the first aspect of the present application, the number of lenses of the first projection sub-lens is 2 times or more than the number of lenses of the second projection sub-lens.

According to an embodiment of the first aspect of the application, the lighting assembly comprises: an illumination source configured to emit multiple monochromatic illumination light; a collimation device; a color combining device; a light homogenizing device; and a polarizing device, wherein the collimating device and the color combining device are disposed in an optical path between the illumination light source and the polarizing device, and are configured to collimate the multiple monochromatic illumination lights into one path of color combining illumination light, the optical path of the color combining illumination light is perpendicular to the optical axis of the first projection sub-lens, and the polarizing device is configured to polarize the color combining illumination light into the polarized illumination light.

According to an embodiment of the first aspect of the present application, the polarizing device is a first polarizer configured to pass polarized light having a first polarization state and block polarized light having a second polarization state, and the polarization splitting component is configured to reflect polarized light having the first polarization state and transmit polarized light having the second polarization state, wherein the polarization directions of the first polarization state and the second polarization state are perpendicular to each other.

According to an embodiment of the first aspect of the present application, the first projection sub-lens and the second projection sub-lens together meet a projection requirement of an optical system.

According to an embodiment of the first aspect of the present application, the display chip is an LCoS chip.

According to a second aspect of the present application, there is provided a head-mounted display device characterized by comprising:

at least one miniature projection module; the method comprises the steps of,

at least one lens unit, a lens frame, two lens legs and a calculating unit; the miniature projection module is arranged in the area of the glasses leg close to the glasses frame. According to an embodiment of the second aspect of the present application, an optical axis of the first projection sub-lens is consistent with an extending direction of the temple.

According to an embodiment of the second aspect of the present application, the at least one lens unit is an optical waveguide, and includes an in-coupling region and an out-coupling region.

According to an embodiment of the second aspect of the present application, the optical axis of the second projection sub-lens is aligned with the center of the coupling-in region.

Additional embodiments and features are set forth in part in the description which follows and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by practice of the disclosed subject matter. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings which form a part of this disclosure.

Drawings

The technical scheme of the present application will be described in further detail with reference to the accompanying drawings and examples. In the drawings, like reference numerals are used to refer to like parts unless otherwise specified. Wherein:

FIG. 1 is a schematic perspective view of a miniature projection module optical system according to some embodiments of the present application;

FIG. 2A is a front plan view of a miniature projection module optical system according to some embodiments of the present application;

FIG. 2B is a plan left side view of the portion of FIG. 2A within the dashed box;

FIG. 3A is a schematic perspective view of AR glasses according to some embodiments of the present application;

FIG. 3B is a front plan view of AR glasses according to some embodiments of the present application;

fig. 3C is a right side plan view of AR glasses according to some embodiments of the present application.

Detailed Description

The inventive concept will now be described in further detail with reference to specific examples. It is noted that the examples set forth herein are only for the purpose of clearly illustrating the inventive concepts of the present application and are not to be construed as limiting the application. The technical features of the micro projection module and the head-mounted display device related to the micro projection module can be combined arbitrarily to form a new embodiment on the premise of not conflicting as long as the natural law or technical specification is not violated.

In the description of the present application, it should be noted that, for the azimuth words such as terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the azimuth and positional relationships are based on the azimuth or positional relationships shown in the drawings, it is merely for convenience of describing the present application and simplifying the description, and it is not to be construed as limiting the specific scope of protection of the present application that the device or element referred to must have a specific azimuth configuration and operation.

It should be noted that the terms "first," "second," and the like in the description and in the claims are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

The terms "comprises" and "comprising," along with any variations thereof, in the description and claims, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It is noted that, as used in the present application, the terms "substantially," "about," and the like are used as terms of approximation of a table, not as terms of degree of the table, and are intended to illustrate inherent deviations in measured or calculated values that will be recognized by those of ordinary skill in the art.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intermediaries, or both elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Various units, circuits, or other components may be described or described as "configured to" perform a task or tasks. In such contexts, "configured to" implies that the structure (e.g., circuitry) is used by indicating that the unit/circuit/component includes the structure (e.g., circuitry) that performs the task or tasks during operation. Further, "configured to" may include a general-purpose structure (e.g., a general-purpose circuit) that is manipulated by software and/or firmware to operate in a manner that is capable of performing one or more tasks to be solved. "configured to" may also include adjusting a manufacturing process (e.g., a semiconductor fabrication facility) to manufacture a device (e.g., an integrated circuit) suitable for performing or executing one or more tasks.

The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the specification and the appended claims, the singular forms "a," "an," and "the" are intended to cover the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the term "if" may be interpreted to mean "when..or" at..times "or" in response to a determination "or" in response to detection "depending on the context. Similarly, the phrase "if a condition or event is identified" or "if a condition or event is detected" may be interpreted to mean "upon identification of the condition or event," or "upon detection of the condition or event, depending on the context.

It is pointed out that the embodiments shown in the drawings are only for the purpose of illustrating and explaining the inventive concept in detail and image, which are not necessarily drawn to scale in terms of size and structure nor are they to be construed as limiting the inventive concept.

Fig. 1 is a schematic perspective view of an optical system of a micro-projection module according to an embodiment of the application, wherein the micro-projection module includes an illumination assembly 10, a relay assembly 20, a display chip 30 and a projection assembly 40. The illumination assembly 10 is configured to provide polarized illumination light having the same polarization state. The relay assembly 20 is configured to transmit at least a portion of polarized illumination light from the illumination assembly 10 to the display chip 30. The display chip 30 is used to modulate the polarized illumination light into polarized image light with image information and transmit the polarized image light to the projection assembly 40 again through the relay assembly 20. The projection assembly 40 is used to project the modulated polarized image light into an image to other optical components of the head mounted display device, such as an optical waveguide.

As shown in fig. 1, R represents red light, G represents green light, B represents blue light, and W represents white light. In order to distinguish polarized illumination light from polarized image light, polarized illumination light in the present application is represented by S polarized light/P polarized light, and polarized image light is represented by S 'polarized light/P' polarized light. In the figure, the solid line represents the illumination light path, the dotted line represents the projection light path, and correspondingly, the illumination light path and the optical element passing through the illumination light path form an illumination system, and the projection light path and the optical element passing through the projection light path form a projection system, which will not be described in detail.

Specifically, as shown in fig. 2A-2B, fig. 2A is a front plan view of the optical system of the micro-projection module, and fig. 2B is a left plan view of the portion inside the dashed frame in fig. 2A. The illumination assembly 10 includes an illumination source 11, a collimation device 12, a color combining device 13, a dodging device 14, and a polarization device 15. The illumination assembly 10 is configured to provide polarized illumination light having the same polarization state.

The illumination source 11 may further include a first light source 111, a second light source 112 and a third light source 113. Optionally, the first light source 111 is a red light source, the second light source 112 is a green light source, and the third light source 113 is a blue light source. The light emitting surfaces of the first light source 111 and the third light source 113 may be disposed on the same plane, and the two light emitting surfaces are disposed in close proximity. It will be appreciated that the color, type, number and combination of the illumination sources may be other, and are not limited in this disclosure.

The collimating device 12 includes a first collimating lens group 121 and a second collimating lens group 122, where each of the first collimating lens group 121 and the second collimating lens group 122 includes at least one optical lens, and optionally an optical lens group formed by a spherical lens and a cylindrical lens, or an optical lens group formed by two types of lenses of two types of spherical lens, cylindrical lens, and aspherical lens, or any combination of two types of lenses, that is, the optical lens surfaces forming the collimating lens group are not limited in the present application.

The color combining device 13 includes a first selective reflection film 131, a second selective reflection film 132, and a wedge prism 133. The wedge prism 133 has two oppositely disposed surfaces that are at an angle other than 0 to each other. The first selective reflection film 131 and the second selective reflection film 132 are respectively disposed on two opposite surfaces of the wedge prism 133. The first collimating lens group 121 is used for converging and collimating the light emitted by the second light source 112 and transmitting the light to the first selective reflecting film 131, and the second collimating lens group 122 is used for converging and collimating the light emitted by the first light source 111 and the third light source 113 and transmitting the light to the second selective reflecting film 132.

In this alternative embodiment, the first selective reflection film 131 is used to reflect blue light and transmit green light, and the second selective reflection film 132 is used to reflect red light and transmit green and blue light. The first selective reflection film 131 is disposed on the lower surface of the wedge prism 133 to face the second light source 112, and the second selective reflection film 132 is disposed on the upper surface of the wedge prism 133 to face the first light source 111 and the third light source 113. Green light emitted from the second light source 112 is collimated by the first collimating lens group 121 and then sequentially passes through the first selective reflecting film 131, the wedge prism 133 and the second selective reflecting film 132; the red light emitted from the first light source 111 is collimated by the second collimating lens group 122 and then reflected by the second selective reflecting film 132; blue light emitted from the third light source 113 is collimated by the second collimating lens group 122, sequentially passes through the second selective reflecting film 132 and the wedge-shaped prism 133, is reflected by the first selective reflecting film 131, passes through the wedge-shaped prism 133 and the second selective reflecting film 132 again, and then is combined with the red light and the green light into a beam of white light, and passes through the light homogenizing device 14 to become uniform illumination light. The material and the transmittance and reflectance ratio of the selective reflection film are selected according to the specific color and type of the illumination source, and are not limited to the above-described selective transmittance and reflectance properties. The light homogenizing device 14 may be a fly's eye lens or other commonly used light homogenizing element for obtaining a uniform illumination distribution.

The uniform illumination light obtained after passing through the light uniformizing device 14 passes through the polarizing device 15 to become polarized illumination light having the first polarization state. The polarizing device 15 may be a first polarizer configured to pass only polarized light having a first polarization state and to block polarized light having a second polarization state. The polarizing device 15 may also be a first polarization multiplexing element for passing only polarized light having the first polarization state and converting polarized light having the second polarization state into polarized light having the first polarization state. Wherein the polarization directions of the polarized light with the first polarization state and the polarized light with the second polarization state are perpendicular to each other, for example, the polarized light with the first polarization state may be S light in the linearly polarized light, and the polarized light with the second polarization state may be P light in the linearly polarized light.

The relay assembly 20 includes a relay lens 21 and a polarization splitting assembly 22. The relay assembly 20 is configured to transmit polarized illumination light from the illumination assembly 10 to the display chip 30.

Optionally, the relay lens 21 is disposed between the light homogenizing device 14 and the polarizing device 15, and the uniform illumination light from the light homogenizing device 14 is transmitted through the relay lens 21 and then converted into polarized illumination light by the polarizing device 15, and enters the polarization splitting component 22.

The polarization beam splitter 22 further includes a first right angle prism 221, a second right angle prism 222, and a polarization beam splitter 223. The first right angle prism 221 and the second right angle prism 222 are isosceles right angle prisms, and the first right angle prism 221 includes a first inclined surface 2211, a first side surface 2212, and a first bottom surface 2213. The second right angle prism 222 includes a second inclined surface 2221, a second side surface 2222, and a second bottom surface 2223. The first inclined surface 2211 is disposed opposite to the second inclined surface 2221, and the polarization splitting element 223 is disposed between the first inclined surface 2211 and the second inclined surface 2221. The polarization splitting element 223 may be a polarization splitting film, and the polarization splitting component 22 is a PBS prism. Illustratively, during the assembly process, a polarizing beam splitter film may be coated on the first inclined surface 2211 and then the first right angle prism 221 may be glued to the second inclined surface 2221 of the second right angle prism 222; the second inclined surface 2221 may be coated with a polarizing beam splitter film, and the second right angle prism 222 may be glued to the first inclined surface 2211 of the first right angle prism 221. The second bottom surface 2223 may provide a mounting reference for the polarizer 15, the polarizer 15 may be attached to the second bottom surface 2223, and the relay lens 21 may be attached to the surface of the polarizer 15 by providing a mounting reference for the polarizer 15.

It is understood that the polarization beam splitter 22 includes a first side 2212, a first bottom 2213, a second side 2222 and a second bottom 2223. The first side 2212 is opposite to and parallel to the second side 2222, the first bottom 2213 is opposite to and parallel to the second bottom 2223, and the first side 2212 connects the first bottom 2213 and the second bottom 2223 and is perpendicular to both sides. The second bottom surface 2223 is configured to receive polarized illumination light from the illumination assembly 10, where the polarized illumination light is reflected at the polarization splitting element 223, turned 90 ° to reach the display chip 30 through the second side surface 2222, and the polarized image light modulated by the display chip 30 and having the polarization direction converted is reversely transmitted through the second side surface 2222 again, and is transmitted from the polarization splitting element 223 and then exits through the first side surface 2212.

The polarization beam splitter 223 is configured to reflect polarized light having a first polarization state and transmit polarized light having a second polarization state. The polarization directions of the first polarization state and the second polarization state are mutually perpendicular.

The display chip 30 is configured to modulate the polarized illumination light into polarized image light with image information and change its polarization state, and illustratively, converts polarized light having a first polarization state into polarized light having a second polarization state, the polarization directions of the first and second polarization states being orthogonal to each other. The display chip 30 is preferably an LCoS chip, and the S polarized light incident on the surface of the LCoS chip is modulated into P' polarized light with image information due to the characteristics of the LCoS chip. It can be understood that, since the LCoS chip is a polarization light modulation device, no additional polarization light modulation device is needed, and if other display chips are adopted, a polarization light modulation device is needed to be additionally arranged on the surface of the display chip to modulate the polarization state of the polarized image light.

The projection assembly 40 includes a projection lens 41. The projection lens 41 further comprises a first projection sub-lens 411 and a second projection sub-lens 412. The projection assembly 40 is configured to project the modulated polarized image light into an image to other optical components of the head mounted display device, such as an optical waveguide.

In an alternative embodiment, the polarization beam splitter 223 transmits the P polarized light while reflecting the S polarized light, the polarizer 15 is an S polarizer, the uniform illumination light passing through the light homogenizing device 14 passes through the polarizer 15 and becomes an S polarized light, the S polarized light is incident perpendicular to the second bottom surface 2223, enters the second right angle prism 222, enters the polarization beam splitter 22 and is reflected at the polarization beam splitter 223, the S polarized light after turning 90 ° exits perpendicular to the second side surface 2222 of the second right angle prism 222, is transmitted to the surface of the display chip 30 through the first projection sub-lens 411, is modulated into the P polarized light through the display chip 30, passes through the first projection sub-lens 411 again reversely, enters the polarization beam splitter 22, is transmitted at the polarization beam splitter 223, exits from the first side surface 2212 of the polarization beam splitter 22, and finally the P polarized light is modulated by the second projection sub-lens 412 to exit to form an image.

The first projection sub-lens 411 is an optical path correction device, that is, a transmissive element with an optical path correction function. The light path correction function refers to a shaping function of a light source, such as beam convergence, in an illumination system, and refers to a balance function of an object-image relationship and aberration in a projection system. Preferably, the first projection sub-lens 411 is a lens group composed of at least two optical lenses, and the first projection sub-lens 411 is disposed in the optical path between the polarization beam splitter 22 and the display chip 30. The first projection sub-lens 411 is disposed outside the second side surface 2222, and the optical axis is perpendicular to the second side surface 2222. In an alternative embodiment, the first projection sub-lens 411 is used to collect and keep the S polarized light emitted from the polarization beam splitter 22 within a specific range, and transmit the S polarized light to the display chip 30, that is, the light passing through the first projection sub-lens 411 is part of the illumination light path.

The polarized image light modulated by the display chip 30 and having image information, in an alternative embodiment, P' polarized light, passes through the first projection sub-lens 411 again, enters the second right angle prism 222 perpendicular to the second side 2222 of the second right angle prism 222, is transmitted at the polarizing beam splitter 223, enters the first right angle prism 221, and exits perpendicular to the first side 2212 of the first right angle prism 221. It will be appreciated that the light passing through the first projection sub-lens 411 is now part of the projection path. That is, for the whole optical system, the first projection sub-lens 411 simultaneously realizes the correction function for the illumination light path and the projection light path, and part of the light paths in the relay system are multiplexed by the illumination system and the projection system, so that the whole micro projection module more accords with the miniaturization condition.

The second projection sub-lens 412 is disposed outside the first side 2212, and the optical axis is perpendicular to the first side 2212. That is, the second projection sub-lens 412 and the first projection sub-lens 411 are disposed at opposite sides of the polarization beam splitter 22, and the optical axes of the two are located on the same line. It is understood that the second projection sub-lens 412 is also an optical path correction device. The second projection sub-lens 412 includes at least one optical lens. Any one of the first projection sub-lens 411 and the second projection sub-lens 412 cannot individually meet the optical requirements of the projection system of the miniature projection module, and the common correction of the first projection sub-lens 411 and the second projection sub-lens 412 to the optical path makes the projection optical path meet the effective focal length requirement of the whole system. It can be understood that, the first projection sub-lens 411 is matched with the second projection sub-lens 412 to meet the optical parameter requirement of the projection system, and also meet the optical parameter requirement of the illumination system, so that the optical path inside the first projection sub-lens 411 is multiplexed by the illumination system and the projection system.

As shown in fig. 1, the color-combining illumination light emitted from the color-combining device 13 sequentially passes through the light-homogenizing device 14 and the polarizer 15 along a first direction and then is converted into polarized illumination light S, the polarized illumination light S turns 90 ° in the polarization splitting component 22 and reaches the display chip 30 along a second direction, the polarized illumination light P 'turns 180 ° and is modulated into polarized image light P' by the display chip 30, and then reaches the polarization splitting component 22 again through the first projection sub-lens 411 in a third direction, and after transmission, the polarized illumination light enters the second projection sub-lens 412 along the third direction, and finally is modulated into projection emergent light through the first projection sub-lens 411 and the second projection sub-lens 412 together and is projected from the micro projection module to form a complete illumination light path and a projection light path, wherein the first direction and the second direction are mutually perpendicular, the second direction and the third direction are mutually parallel and opposite, and the micro projection module is in an L-shaped structure as a whole.

It will be appreciated that in an alternative embodiment, the complete projection lens is composed of two projection sub-lenses, at least one projection sub-lens is disposed between the polarization beam splitter 22 and the display chip 30, and at least one other projection sub-lens is disposed on the other side of the polarization beam splitter 22, so that the overall length dimension of the optical machine is greatly reduced compared to the arrangement of the complete projection lens on the same side of the polarization beam splitter. The first projection sub-lens 411 is used for both an illumination light path and a beam converging of light and a projection light path, so that the size requirement of the PBS prism is reduced while the object-image relationship and the image quality balance are met, the internal space of the optical machine is effectively utilized, the light path is folded on the premise of meeting the total optical path requirement, and the whole volume is reduced; the second projection sub-lens 412 is used for balancing the image quality and expanding the light, so that the chip target image can be projected out of the optical engine without loss, that is, the first projection sub-lens 41 and the second projection sub-lens 412 together meet the projection requirement of the optical system, and the projection is completed. Compared with the traditional miniature projection module, the miniature projection module provided by the application has obvious miniaturization advantage.

It should be noted that, in the present application, the number and the arrangement positions of the projection sub-lenses are not limited by the present application, and it is easy for those skilled in the art to split the projection lens into different numbers of projection sub-lenses and arrange the projection sub-lenses at different positions according to the optical design requirements of the projection system and the illumination system.

Besides the optical system of the micro projection module, the micro projection module further comprises a power supply unit, a shell, structural connectors among optical elements, a heat dissipation unit and the like.

The application also provides a head-mounted display device, which comprises at least one micro projection module, at least one lens unit, a frame for installing the lens unit and the micro projection module, a glasses leg for wearing, and a calculating unit for processing data and image information, wherein the micro projection module outputs an image according to an instruction sent by the calculating unit. An exemplary detailed description of a head-mounted display device including the micro-projection module will be given below with reference to AR glasses.

As shown in fig. 3A to 3C, the AR glasses include a micro-projection module 1 for mounting a frame 2 of a lens unit, a left lens unit 3, a right lens unit 4, a calculation unit 5, and a temple 6 for wearing. Here, the left lens unit 3 and the right lens unit 4 are fixedly mounted in the frame 2, and the temple 6 may be connected to the frame 2 in any manner, for example, in a flexible manner, or in the form of a hinge, or in a fixed manner, or in a detachable manner, thereby forming a main body portion of the AR glasses. The electronic components of AR glasses may optionally be mounted on the temple 6 and/or the frame 2 or embedded/buried in the material thereof. The electronic components include, but are not limited to, a computing unit 5 for processing data and image information, an eye tracker, a depth sensor, a spatial sensor, a position sensor, combinations thereof, and the like.

In an alternative embodiment, the number of the micro-projection modules 1 is two, and the micro-projection modules are respectively mounted on the left and right legs 6 near the frame 2, and optionally, the micro-projection modules are mounted on the inner sides of the legs. When the micro projection module 1 is mounted on the temple 6, the optical axis of the first projection sub-lens 411 is disposed along the extending direction of the temple 6, such that the optical axis of the second projection sub-lens 412 is substantially perpendicular to the lens unit. The left lens unit 3 includes a coupling-in area 31 and a coupling-out area 32, the coupling-in area 31 is disposed at the upper left corner of the left lens unit 3, and the optical axis of the second projection sub-lens 412 of the micro-projection module 1 is aligned with the center of the coupling-in area 31; the right lens unit 4 includes a coupling-in region 41 and a coupling-out region 42, the coupling-in region 41 is disposed at the upper right corner of the right lens unit 4, and the optical axis of the second projection sub-lens 412 of the micro-projection module 1 is aligned with the center of the coupling-in region 41. The image light projected by the micro projection module 1 is coupled into the optical waveguide through the coupling-in area, is coupled out from the coupling-out area after turning and expanding pupil, and is finally received by eyes of a user. The number of lenses of the first projection sub-lens 411 may be 3-6, the number of lenses 412 of the second projection sub-lens may be 1-3, and the number of lenses of the first projection sub-lens is preferably 2 times or more than that of lenses of the second projection sub-lens, so that the second projection sub-lens 412 does not protrude out of the micro projection module too much after the assembly is completed, the micro projection module 1 is integrally close to an L-shaped structure, the long side of L corresponds to the first projection sub-lens portion, and the short side of L corresponds to the illumination light source portion. From the side, the glasses leg 6 and the glasses frame 2 of the AR glasses also form an L-shaped structure, the long side of L corresponds to the glasses leg 6, the short side of L corresponds to the glasses frame 2, the shape of the miniature projection module 1 is matched with the shape of the AR glasses, and when the miniature projection module is installed on the glasses leg in the above mode, other spaces of the AR glasses are not excessively occupied, so that more comfortable wearing experience is provided for users.

Similarly, in combination with the specific shape and spatial structure of the head-mounted display device, the shape of other lens units, the arrangement position of the coupling region, the arrangement position of the micro-projection module, and the like can also be considered, which is not limited in any way by the present application.

The foregoing has outlined the basic principles, features, and advantages of the present application. It will be understood by those skilled in the art that the present application is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present application, and various changes and modifications may be made therein without departing from the spirit and scope of the application, which is defined by the appended claims. The scope of the application is defined by the appended claims and equivalents thereof.

Claims

1. A miniature projection module, comprising:

2. The miniature projection module of claim 1, wherein the number of lenses of the first projection sub-lens is 2 times and more than the number of lenses of the second projection sub-lens.

3. The miniature projection module of claim 1, wherein the illumination assembly comprises: an illumination source configured to emit multiple monochromatic illumination light; a collimation device; a color combining device; a light homogenizing device; and a polarizing device, wherein the collimating device and the color combining device are disposed in an optical path between the illumination light source and the polarizing device, and are configured to collimate the multiple monochromatic illumination lights into one path of color combining illumination light, the optical path of the color combining illumination light is perpendicular to the optical axis of the first projection sub-lens, and the polarizing device is configured to polarize the color combining illumination light into the polarized illumination light.

4. The miniature projection module according to claim 3, wherein the polarizing device is a first polarizer configured to pass polarized light having a first polarization state and block polarized light having a second polarization state, and the polarization splitting assembly is configured to reflect polarized light having the first polarization state and transmit polarized light having the second polarization state, wherein the polarization directions of the first and second polarization states are perpendicular to each other.

5. The miniature projection module of claim 1, wherein the first projection sub-lens and the second projection sub-lens together meet a projection requirement of an optical system.

6. The miniature projection module of claim 1, wherein the display chip is an LCoS chip.

7. A head-mounted display device, comprising:

at least one miniature projection module according to any one of claims 1 to 6; the method comprises the steps of,

at least one lens unit, a lens frame, two lens legs and a calculating unit; the miniature projection module is arranged in the area of the glasses leg close to the glasses frame.

8. The head mounted display device of claim 7, wherein an optical axis of the first projection sub-lens coincides with an extension direction of the temple.

9. The head mounted display device of claim 7, wherein the at least one lens unit is an optical waveguide comprising an in-coupling region and an out-coupling region.

10. The head mounted display device of claim 9, wherein an optical axis of the second projection sub-lens is aligned with a center of the in-coupling region.