CN217739618U - Optical imaging module and near-to-eye display device - Google Patents

Abstract

The utility model provides an optical imaging module and a nearly eye display device, the optical imaging module includes: the first lens is close to the object side of the optical imaging module; a second lens on an image side of the first lens, wherein the second lens is cemented with the first lens; a transflective layer located at a position of the glue between the first lens and the second lens; a second phase retarder on an image side of the second lens; and a reflective polarizer disposed on an image side of the second phase retarder.

Description

Optical imaging module and near-to-eye display device

Technical Field

The utility model relates to the field of optical technology, especially, relate to an optical imaging module and near-to-eye display device.

Background

Virtual Reality, VR for short, is a technology that provides an immersive sensation in an interactive three-dimensional environment generated on a computer by comprehensively using a computer graphics system and various interface devices such as Reality and control. The general VR glasses are mainly configured by two lenses, images seen by the left eye and the right eye are respectively and independently separated and are continuously and alternately displayed on a screen, and the stereoscopic effect of depth of field can be generated by adding the physiological characteristic of the persistence of vision of human eyes.

Among the optical amplification module structure among the prior art, for satisfying the imaging quality in the optical amplification module, contain a plurality of optical devices in the module usually, because each optical device needs certain installation space, the optical amplification module that consequently constitutes a plurality of optical devices is often big size and volume all, especially can not satisfy the display requirement of intelligent VR (Virtual Reality) wearing equipment little space high magnification. The optical imaging module in a VR device is an important design factor that determines the imaging quality and size of the device.

VR probably can divide two kinds of structures on the visual field at present, and the VR is focused surely (be single slice (multi-disc) VR and do not support to zoom and transfer), the VR of zooming (be two above VR, zoom and can adapt to different myopia crowd). Most VR optical technologies in the field mostly adopt a folded optical path technology, which is 2-piece or three-piece, the total optical length of the module is basically about 17mm-207mm (the distance from the vertex of the human eye to the image plane), and the resolution is basically about 1.6k for a single eye.

Most of the existing VR technologies in the market have low resolution, which brings problems, such as low resolution, screen window effect of imaging, and dizziness after long-time wearing; in addition, VR is not suitable for long-term wearing because the optical total length of the optical module is too long and bulky. With the continuous development of VR technology, audience groups of VR devices are also more and more extensive, but most of mechanical structures and optical modules are heavy and thick.

In addition to VR technology, other types of mixed reality technology (e.g., augmented reality AR) have similar drawbacks.

The statements in this background section merely represent techniques known to the public and are not, of course, representative of the prior art.

SUMMERY OF THE UTILITY MODEL

Most of the prior VR technology has low resolution, has screen window effect in imaging and can be dizzy after being worn for a long time; in addition, VR is not suitable for long-term wearing because the optical total length of the optical module is too long and the optical module is bulky. In view of at least one defect of the prior art, the utility model provides an optical imaging module, optical imaging module includes:

the object side close to the optical imaging module is a first lens;

a second lens on an image side of the first lens, wherein the second lens is cemented with the first lens to form a cemented lens;

a transflective layer located at a position of the glue between the first lens and the second lens;

a second phase retarder on an image side of the second lens; and

a reflective polarizer disposed on an image side of the second phase retarder.

According to an aspect of the present disclosure, the optical imaging module further includes a first phase retarder disposed on a side of the first lens close to the object side.

According to one aspect of the present disclosure, the first phase retardation plate and the second phase retardation plate are quarter-wave plates, optical axes of the first phase retardation plate and the second phase retardation plate are orthogonally disposed, and the first phase retardation plate is a separate element or is integrated with a display screen.

According to an aspect of the present invention, the first lens and the second lens conform to one of the following situations:

the surface of the image side of the first lens is concave; the object side surface of the second lens is convex;

the surface of the image side of the first lens is convex; the object side surface of the second lens is concave;

wherein the semi-transparent semi-reflecting layer has a contour which is consistent with the image side surface of the first lens and the object side surface of the second lens.

According to an aspect of the present invention, the first lens has a positive power or a negative power, and the cemented lens has a positive power.

According to an aspect of the disclosure, the optical imaging module further includes a third lens, and the third lens is located between the second phase retarder and the second lens or located on the image side of the reflective polarizer.

According to an aspect of the present disclosure, the third lens has a positive power or a negative power, and an object-side surface or an image-side surface of the third lens is a plane or a non-plane.

According to an aspect of the present disclosure, the second phase retarder and the reflective polarizer are sequentially attached to the plane or the non-plane.

According to an aspect of the present disclosure, the reflection focal length of the transflective layer is F12, the focal length of the optical imaging module is F, and the following relationship is satisfied: f12 is more than or equal to 1.1 and less than or equal to 4F.

According to an aspect of the present disclosure, the optical imaging module further includes a fourth lens;

wherein the fourth lens is positioned on the object side of the first lens; or alternatively

The fourth lens is positioned between the second lens and a third lens, and the third lens is positioned on the object side of a second phase retardation plate; or

The fourth lens is positioned between the second lens and a second phase retarder, and the third lens is positioned on the image side of the reflective polarizer; or

The fourth lens is positioned on the image side of the reflective polarizer, and the third lens is positioned on the object side of the second phase retardation plate; or

The fourth lens is positioned on the image side of the third lens, and the third lens is positioned on the image side of the reflective polarizer.

The utility model also provides a near-to-eye display device, include:

a display screen; and

the optical imaging module is arranged on the downstream of the optical path of the display screen.

According to the embodiment of the invention, the cemented lens is used for adjusting the diopter of light, and the light after undergoing diopter adjustment enters human eyes after passing through the folded light path. The design of the cemented lens can save VR assembly space while improving resolution, and is beneficial to light and thin design of VR modules.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 illustrates an optical imaging module according to one embodiment of the present invention;

FIG. 2 illustrates an optical imaging module in accordance with a preferred embodiment of the present invention;

FIG. 3 shows a variation of the embodiment of FIG. 2;

FIG. 4 illustrates an optical imaging module in accordance with a preferred embodiment of the present invention;

FIG. 5 illustrates an optical imaging module in accordance with a preferred embodiment of the present invention;

6A, 6B and 6C illustrate the optical path layout, MTF diagram and field curvature and distortion diagram of the optical imaging module according to the first embodiment of the present invention;

7A, 7B and 7C show the optical path layout, MTF diagram and field curvature and distortion diagram of the optical imaging module according to the second embodiment of the invention;

8A, 8B and 8C show the optical path layout, MTF diagram and field curvature and distortion diagram of the optical imaging module according to the third embodiment of the invention;

9A, 9B and 9C show the optical path layout, MTF diagram and field curvature and distortion diagram of the optical imaging module according to the fourth embodiment of the invention;

10A, 10B and 10C show the optical path layout, MTF diagram and field curvature and distortion diagram of an optical imaging module according to the fifth embodiment of the present invention;

11A, 11B and 11C show the optical path layout, MTF diagram and field curvature and distortion diagram of an optical imaging module according to the sixth embodiment of the invention;

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected" and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, either mechanically, electrically or communicatively coupled; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be noted that. Unless otherwise specifically stated or limited, the terms "sheet" and "film" are to be construed broadly, and may include, for example, individual optical elements as well as layers of film applied to a lens or transparent substrate.

In the present application, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation of the first and second features not being in direct contact, but being in contact with another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. In order to simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present disclosure may repeat reference numerals and/or reference letters in the various examples for purposes of simplicity and clarity and do not in itself dictate a relationship between the various embodiments and/or arrangements discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize the application of other processes and/or the use of other materials.

Embodiments of the present invention will be described with reference to the accompanying drawings, and it should be understood that the embodiments described herein are merely illustrative and explanatory of the present invention, and are not restrictive of the invention.

Fig. 1 shows an optical imaging module 100 according to an embodiment of the present invention, and the optical imaging module 100 is used for forming a folded optical path between an image source (light source) and a human eye to project image light to the human eye. Described in detail below with reference to fig. 1. In the drawings and the following description, the right side is the object side, i.e., the side on which an image source or an object to be imaged is placed, and may also be referred to as an optical path upstream; the left side is the image side, i.e. the side on which the observer is located, and may also be referred to as the optical path downstream.

As shown in fig. 1, the optical imaging module 100 includes a first phase retarder 101, a first lens 102, a transflective layer 104, a second lens 103, a second phase retarder 105, and a reflective polarizer 106, which are sequentially disposed from an object side to an image side.

The first phase retarder 101 is disposed on the object side of the first lens 102, and is configured to receive image light received from an image source, the image light being preferably linearly polarized light, as indicated by reference numeral E1 in fig. 1. The image source may be, for example, a display screen or an object to be imaged.

The first lens 102 is adjacent to the first phase retardation plate 101, the second lens 103 is located on the image side of the first lens 102, and the second lens 103 and the first lens 102 are cemented together to constitute a cemented lens group. The transflective layer 104 is located at a position of the glue between the first lens 102 and the second lens 103, i.e. at a glue surface of the two. The transflective layer 104 has a transmission and reflection capability, and reflects a portion of a light beam incident thereon, while allowing another portion to transmit. The reflection ratio and the transmission ratio of the transflective layer 104 can be 50%, also can be 40% and 60% respectively, also can adopt the transflective layer of other reflection ratios and transmission ratios as required, the utility model discloses do not limit the concrete reflection ratio and the transmission ratio of the transflective layer 104. The transflective layer 104 may be sandwiched as a coating film between the first lens 102 and the second lens 103. The transflective layer 104 is disposed between the first lens 102 and the second lens 103, and may have an average light reflectance of at least 30% in a desired or predetermined plurality of wavelengths, and may have an average light transmittance of at least 30% in a desired or predetermined plurality of wavelengths. In some embodiments, the desired or predetermined plurality of wavelengths may be a single continuous range of wavelengths (e.g., the visible range of 400nm-700 nm), or may be a plurality of continuous ranges of wavelengths. The transflective layer 104 may be a notch reflector and the desired or predetermined plurality of wavelengths may include one or more wavelength ranges at least some of which have a full width half maximum reflection band of no more than 100nm or no more than 50 nm.

In the present invention, the first lens 102, the semi-transparent and semi-reflective layer 104, and the second lens 103 constitute a semi-transparent and semi-reflective lens, or a cemented lens. The image side surface of the first lens 102 and the object side surface of the second lens 103 are of the same surface type and thus may be cemented together.

According to a preferred embodiment of the present invention, the first lens 102 and the second lens 103 conform to one of the following situations:

the surface on the image side of the first lens 102 is concave; the object side surface of the second lens 103 is convex;

the surface on the image side of the first lens 102 is convex; the object side surface of the second lens 103 is concave.

Wherein the transflective layer 104 has a contour conforming to an image-side surface of the first lens 102 and an object-side surface of the second lens 103.

According to a preferred embodiment of the present invention, the first lens 102 has a positive optical power, the second lens 103 has a positive optical power, and the cemented lens has a positive optical power. Or alternatively, the first lens 102 has a negative optical power, the second lens 103 has a positive optical power, and the combined cemented lens has a positive optical power. Or alternatively, the first lens 102 has a positive optical power, the second lens 103 has a negative optical power, and the combined cemented lens has a positive optical power.

A second phase retarder 105 is on the image side of the second lens 103, and a reflective polarizer 106 is disposed on the image side of the second phase retarder 105, close to the eye of the viewer. The reflective polarizer 106 has a polarization direction that will be transmitted through the reflective polarizer 106 when the polarization direction of the polarized light incident thereon is the same as the polarization direction of the reflective polarizer 106; when the polarization direction of the polarized light incident thereon is orthogonal to the polarization direction of the reflective polarizer 106, the polarized light will be reflected. The reflective polarizer includes a planar configuration or a curved configuration. The curved-surface-configuration reflective polarizer has the advantages of providing extra diopter capacity and imaging quality optimization freedom, and realizing an optical imaging module with smaller thickness and better optical quality. The reflective polarizer 106 is configured to achieve the performance of transmission when the incident light is aligned with the polarization direction and total reflection when the incident light is orthogonal to the polarization direction. The reflective polarizer 106 may be a notch reflective polarizer whose reflection band may match or substantially match the reflection band of the transflective layer 104.

In the optical imaging module 100, the first lens 102 and the second lens 103 share the function of converging and imaging.

The optical principles and operation of the optical imaging module 100 shown in fig. 1 are described in detail below. The linearly polarized light beam E1 emitted by the object-side display screen is changed into a circularly polarized light beam E2 through the first phase retarder 101, the circularly polarized light beam E2 is sequentially changed into a linearly polarized light beam E3 through the first lens 102, the semi-transparent and semi-reflective layer 104, the second lens 103 and the second phase retarder 105, the linearly polarized light beam E3 is incident on the reflective polarizer 106, the polarization direction of the reflective polarizer 106 is orthogonal to the polarization direction of the linearly polarized light beam E3, the linearly polarized light beam E3 is reflected by the reflective polarizer 106, the linearly polarized light beam E3 is changed into a circularly polarized light beam E5 through the second phase retarder 105 again as shown by the linearly polarized light beam E4, a circularly polarized light beam E6 is reflected on the semi-transparent and semi-reflective layer 104, the linearly polarized light beam E7 is changed into a linearly polarized light beam E7 through the second phase retarder 105 for the third time, the polarization direction of the linearly polarized light beam E7 is the same as the polarization direction of the reflective polarizer 106, and therefore the linearly polarized light beam E7 can enter the image side through the reflective polarizer 106, and is projected to the eyes of an observer and forms an image.

In addition, as will be readily understood by those skilled in the art, the optical imaging module 100 may not include the first retarder 101. For example, when the optical imaging module 100 is used with a display screen, the display screen may be internally integrated with the first phase retardation plate 101, so that the light emitted from the display screen is circularly polarized light E2 (or elliptically polarized light), which is also within the scope of the present invention. In this case, the optical imaging module 100 includes: the first lens 102, the transflective layer 104, the second lens 103, the second phase retardation plate 105, and the reflective polarizer 106, which are sequentially disposed from the object side to the image side, have substantially the same operation principle as that shown in fig. 1, and are not described herein again.

According to an embodiment of the present invention, the first phase retardation plate 101 and the second phase retardation plate 105 are quarter-wave plates, so that it is just possible to adjust linearly polarized light incident thereon to circularly polarized light or to adjust circularly polarized light to linearly polarized light. The quarter-wave plate may be a quarter-wave retarder at least one of a desired or predetermined plurality of wavelengths.

According to an embodiment of the present invention, the optical axes of the first phase retarder 101 and the second phase retarder 105 are orthogonally disposed, so as to achieve the effect of rotating and reversing polarized light. In addition, the first phase retarder 101 may be a separate element or may be integrated with a display screen.

In the above embodiment, the cemented lens (102, 103) is used to adjust the diopter of light, and the light after performing the diopter adjustment enters the human eye after passing through the folded optical path. The design of the cemented lens can save VR assembly space, and is beneficial to the light and thin design of a VR module.

Fig. 2 shows an optical imaging module 200 according to a preferred embodiment of the present invention, which has substantially the same structure as the optical imaging module 100 shown in fig. 1, and further includes a third lens 207, where the third lens 207 is located between the second phase retarder 105 and the second lens 103. The third lens 207 may partially assume the functions of imaging and diopter adjustment.

FIG. 3 shows a variation of the embodiment of FIG. 2 where a third lens 207 is positioned on the image side of the reflective polarizer 106.

Compared with the embodiment of fig. 1, the third lens 207 is added in the embodiment of fig. 2 and 3, and the third lens 207 can help to image and adjust diopter, but does not substantially change the polarization state of light, so the working principle of the optical imaging module 200 of fig. 2 and 3 is substantially the same as that of fig. 1, and is not repeated here.

According to a preferred embodiment of the present invention, the third lens 207 has a positive power or a negative power. The object-side surface or the image-side surface of the third lens element 207 may be a plane or a non-plane (e.g., spherical or aspherical), and the other surface may be a convex surface or a concave surface. In one embodiment, as shown in fig. 4, the third lens 207 has a flat object-side surface and a convex image-side surface, and the second phase retarder 105 and the reflective polarizer 106 are sequentially attached to the flat surface.

According to a preferred embodiment of the present invention, the focal length of reflection of the transflective layer 104 is F12, and the focal lengths of the optical imaging modules 100 and 200 are F, which satisfy the following relationship: f12 is more than or equal to 1.1F and less than or equal to 4F.

The reflection focal length of the semi-transparent and semi-reflective layer is set to be F12, the optimal setting can be carried out according to different embodiments, and F12 is required to be more than or equal to 1.1F and less than or equal to 4F, wherein F is the focal length of the imaging module system. The thickness of the module is defined as H, the distance from the leftmost reflective polarizer to the imaging surface of the screen is defined, and H is less than or equal to 30mm.

Fig. 5 shows an optical imaging module 300 according to another embodiment of the present invention, which has substantially the same structure as the optical imaging module 200 shown in fig. 2, and further includes a fourth lens 308, where the fourth lens 308 is located on an object side of the first lens 102, for example, the fourth lens 308 may be located on an object side of the first retarder 101, as shown in fig. 5, or may be located between the first retarder 101 and the first lens 102. The fourth lens 308 may partially assume the functions of imaging and diopter adjustment.

The position of the fourth lens 308 may be set according to actual design requirements, and besides being located on the object side of the first lens 102, the fourth lens 308 may also be located between the second lens 103 and the third lens 207, and the third lens 207 is located on the object side of the second phase retardation plate 105; or the fourth lens 308 is located between the second lens 103 and the second phase retardation plate 105, and the third lens 207 is located on the image side of the reflective polarizer 106; or the fourth lens 308 is positioned on the image side of the reflective polarizer 106, and the third lens is positioned on the object side of the second phase retardation plate 105; alternatively, the fourth lens element 308 is positioned on the image side of the third lens element 207, which is positioned on the image side of the reflective polarizer 106.

According to a preferred embodiment of the present invention, there is at least one lens between the first phase retarder 101 and the cemented lens, between the second phase retarder 105 and the cemented lens, and between the third lens 207 and the human eye.

In the embodiment of fig. 5, both the third lens 207 and the fourth lens 308 are included, but the application is not limited thereto, and only the fourth lens 308 may be included instead of the third lens 207, which are all within the protection scope of the application.

The utility model discloses still relate to a near-to-eye display device, including the display screen with as above the optical imaging module, set up the light path low reaches of display screen.

The following describes a specific design of an optical imaging module according to a specific embodiment of the present application.

Example one

The optical path structure of the optical imaging module in the first embodiment is shown in fig. 2. In the short-distance optical magnification imaging module, the focal length F12 of the reflection surface of the semi-transparent and semi-reflective surface contained in the cemented lens group (102, 103) is designed to be equal to the system focal length 2.114F, and the cemented lens group (102, 103) and the third lens 207 are specifically set as shown in the following table 1. The "OBJ" in the table refers to the "thing" established during the simulation, and is located on the left side (eye side) in fig. 2; "Image" refers to an "Image" formed during the simulation, and is located on the right side (display side) in fig. 2. The same is true in other embodiments below.

TABLE 1

Surf	Type	Radius	Thichness	Glass	Diameter	Conic
							OBJ	STANDARD	Infinity	Infinity			0	0
STO	PARAXIAL	Infinity	11		7	0
							3	STANDARD	Infinity	0.3	BK7	40	0
4	STANDARD	Infinity	1.45	D-LAK6	40	0
							5	EVEN ASPHERIC	-212.77	3.657		40	-9.83
6	EVEN ASPHERIC	92.18	6.722	PK3	40	8.01
							7	EVEN ASPHERIC	-70.06	-6.722	MIRROR	40	4.03
8	EVEN ASPHERIC	92.18	-3.657		40	8.01
							9	EVEN ASPHERIC	-212.77	-1.45	D-LAK6	40	-9.83
10	STANDARD	Infinity	-0.3	BK7	40	0.00
							11	STANDARD	Infinity	0.3	MIRROR	40	0.00
12	STANDARD	Infinity	1.45	D-LAK6	40	0.00
							13	EVEN ASPHERIC	-212.77	3.657		40	-9.83
14	EVEN ASPHERIC	92.18	6.722	PK3	40	8.01
							15	EVEN ASPHERIC	-70.06	3.945	H-LAF62	40	4.03
16	EVEN ASPHERIC	-152.67	0.5		40	-0.78
							17	STANDARD	Infinity	0.4	BK7	24	0.00
Image	STANDARD	Infinity			24	0.00

The table 1 analyzes the light propagation direction from the optical design angle, the first row OBJ represents object plane-related design parameters, the second row STO represents diaphragm design parameters of the optical system (the plane type is PARAXIAL plane paramaxial), and the aperture is 7mm; the third row represents the design parameters of a diaphragm formed by a reflection type polaroid and a second phase retarder in the optical module, wherein the diaphragm is of a STANDARD STANDARD surface, is made of BK7 and has a diameter of 40mm; the fourth and fifth lines represent the design parameters of the third lens 207 (the fourth line is plane Radius = infinity, the surface type is a standard surface, the fifth line is an even aspheric surface, the material is D-LAK6, the diameter is 40mm, the sixth and seventh lines refer to the design data of the second lens 103, the surface types are aspheric surfaces, the material is PK3, the diameter is 40mm, the seventh to thirteenth lines represent the reflection and transmission related design data of the light in the reflective polarizer, the second phase retarder, the third lens 207 and the second lens 103 in the cemented lens (102, 103), the fourteenth to sixteenth lines are the design data of the cemented lens (102, 103), the surface types are non-surface, the materials are PK3 and H-LAK62 (the surface types of the fifteenth line and the seventh line in table 1 are the same, and the semi-reflective function is realized), the seventeenth line is the design data of the glass surface, the protective surface is the standard surface BK, and the eighth line is the semi-transparent LCD surface type, and the protective surface is 7.

TABLE 2

The Even aspheric surface (Even ASPHERE) formula is generally shown as follows:

wherein: r is the distance from a point on the lens to the optical axis, c is the curvature of the apex of the curved surface, K is the conic coefficient, a1, a2, a3,

a4 And a5, a6 and a7 are 2, 4, 6, 8, 10, 12, 14 and 16 sub-surface coefficients respectively.

For example table 1 the fifth row 5 of table 2:

C＝-1/212.77，K＝-9.83，a1＝0，a2＝-1.033*10-5，a3＝3.81*10-8，a4＝-5.2 8*10-11，a5＝-8.68*10-15，a6＝2.53*10-16，a7＝a8＝0

substituting the above coefficients into formula Z is an aspheric expression of the second (image side) surface of the third lens 207, and so on.

The optical path layout of the optical imaging module in the first embodiment is shown in fig. 6A. Fig. 6B shows an MTF graph of an optical imaging module according to the first embodiment. In the MTF curve, FOV:90 DEG, and MTF 80Ip/mm > 0.44. FIG. 6C shows the field curvature and distortion plots for the optical imaging module of example one, where the field curvature is (-0.2, 0.2) and the distortion is < 30%.

TABLE 3

Screen size C (inch)	1.2
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	4000＊4000
		Thickness of optical system (mm)	17
Angle of view FOV (°)	90
		Semi-transmitting semi-reflecting focal length f12	2.114F
eye box-eye movement range	7
		Focal length of system F (mm)	16.57
eye relief-eye distance (mm)	11
		F # -aperture	2.37
Optical outside diameter D (mm)	40
		Distortion Dst of system	-29.00％
Focal length f4 of cemented lens	8.95F

Table 3 shows the design parameters of the optical imaging module in the first embodiment. As can be seen from the data in table 3, with the relevant design parameters in tables 1 and 2, the optical system is a 3-piece structure; the focal length of the cemented lens is 8.95F, when the focal length F12 of the semi-transparent and semi-reflective reflecting surface is 2.114F, and the thickness of the optical system is 17mm, a system focal length of 16.57 can be obtained, and a 90-degree field angle can be further obtained; by designing the aperture disposed in front of the short-distance optical amplification module to be 2.37, that is, the corresponding aperture diameter D is 7mm, a moving-eye range of 7mm can be obtained accordingly.

Meanwhile, the screen size is designed to be 1.2 inches, the eye distance is 11mm, and by combining the MTF graph of the first embodiment of the graph, the horizontal coordinate (spatial frequency per millimeter) value of which the average vertical coordinate (modulation transfer function) of each field of view is higher than 0.44 can be obtained, so that the visual angle resolving power of the short-distance optical amplification module can support the resolution of 4000 x 4000, the distortion rate in the field curvature and distortion graph of the first embodiment of the graph is controlled within the range of (-29%, 0), and the field curvature and distortion rate in the field curvature and distortion graph of the first embodiment of the graph is controlled within the range of (-0.2mm, 0.2mm).

Example two

The optical path structure of the optical imaging module in the second embodiment is shown in fig. 2. In the short-distance optical magnifying imaging module, the focal length F12 of the reflection surface of the half-mirror included in the cemented lens (102, 103) is designed to be equal to the system focal length 2.092F, and the specific design data of the cemented lens (102, 103) and the third lens 207 are as shown in the following tables 4 and 5.

TABLE 4

Surf	Type	Radius	Thichness	Glass	Diameter	Conic
							OBJ	STANDARD	Infinity	Infinity		Infinity		0
2	PARAXIAL	Infinity		0		7									0
							STO	STANDARD	Infinity	9.000		7	0
4	STANDARD	Infinity	0.300	BK7	38.000	0
							5	STANDARD	Infinity	2.732	N-LAK7	38.000	0
6	EVEN ASPHERIC	-110.218	0.131		38.000	23.713
							7	EVEN ASPHERIC	99.832	6.062	K11	38.000	10.000
8	EVEN ASPHERIC	-62.440	-6.062	MIRROR	38.000	3.429
							9	EVEN ASPHERIC	99.832	-0.131		38.000	10.000
10	EVEN ASPHERIC	-110.218	-2.732	N-LAK7	38.000	23.713
							11	STANDARD	Infinity	-0.300	BK7	38.000	0.000
12	STANDARD	Infinity	0.300	MIRROR	38.000	0.000
							13	STANDARD	Infinity	2.732	N-LAK7	38.000	0.000
14	EVEN ASPHERIC	-110.218	0.131		38.000	23.713
							15	EVEN ASPHERIC	99.832	6.062	K11	38.000	10.000
16	EVEN ASPHERIC	-62.440	3.237	H-ZF6	38.000	3.429
							17	EVEN ASPHERIC	-168.604	0.500		38.000	-1.186
18	STANDARD	Infinity	0.400	BK7	25.200	0.000
							Image	STANDARD	Infinity			25.200	0.000

Said table 4 analyzes the light's relay direction from the optical design point of view, the first row OBJ represents object plane related design parameters, the second and third rows represent stop STO design parameters of the optical system (surface type is PARAXIAL plane paramaxial and standard plane), the aperture is 7mm; the fourth row represents the design parameters of a diaphragm formed by a reflection type polaroid and a second phase retarder in the optical module, wherein the diaphragm is a STANDARD STANDARD surface, is made of BK7 and has a diameter of 40mm; the fifth line and the sixth line represent design parameters of the third lens 207 (the fifth line is a plane Radius = infinity and the surface type is a standard surface, the sixth line is an even aspheric surface and is made of N-LAK7 and has a diameter of 38mm, the seventh line and the eighth line represent design data of the second lens 103, the surface types are all aspheric surfaces and are made of K11 and have a diameter of 38mm, the eighth to the tenth lines represent reflection and transmission related design data of light rays in the reflective polarizer, the second phase retarder, the third lens 207 and the second lens 103 in the cemented lens (102-103), the fifteenth to the seventeenth lines are cemented lens (102, 103) design data, the surface types are all non-surface-seeking and are made of K11 and H-ZF6 respectively, the surface types of the sixteenth line and the eighth line in the table are made of the same data, and realize a half-reflection function), the tenth line is a glass design data, the image plane is made of a semi-transparent glass, and the protection plane is made of a screen BK, and the image plane is a ninth screen.

TABLE 5

Surf	Type	Conic	2 order item	Item of 4 th order	Item of order 6	Term of order 8	Term of order 10	Term of 12 th order	14 th order term	Term of order 16
											OBJ	STANDARD		0
2	PARAXIAL	0
											STO	STANDARD		0
4	STANDARD	0
											5	STANDARD	0
6	STANDARD	23.713	0	-6.17E-06	6.20E-08	-4.76E-11	-1.01E-13	7.65E-17	0.0	0.0
											7	EVEN ASPHERIC	10.000	0	-1.73E-05	3.62E-08	-3.75E-11	-1.13E-14	2.20E-17	0.0	0.0
8	EVEN ASPHERIC	3.429	0	2.06E-06	-1.08E-08	2.02E-11	7.44E-15	8.47E-18	0.0	0.0
											9	EVEN ASPHERIC	10.000	0	-1.73E-05	3.62E-08	-3.75E-11	-1.13E-14	2.20E-17	0.0	0.0
10	EVEN ASPHERIC	23.713	0	-6.17E-06	6.20E-08	-4.76E-11	-1.01E-13	7.65E-17	0.0	0.0
											11	STANDARD	0.000
12	STANDARD	0.000
											13	STANDARD	0.000
14	EVEN ASPHERIC	23.713	0	-6.17E-06	6.20E-08	-4.76E-11	-1.01E-13	7.65E-17	0	0
											15	EVEN ASPERIC	10.000	0	-1.73E-05	3.62E-08	-3.75E-11	-1.13E-14	2.20E-17	0	0
16	EVEN ASPHERIC	3.429	0	2.06E-06	-1.08E-08	2.02E-11	-7.44E-15	8.47E-18	0	0
											17	EVEN ASPHERIC	-1.186	0	-2.30E-05	-1.05E-07	5.16E-10	5.24E-13	-3.41E-15	0	0
18	STANDARD	0.000
											Image	STANDARD	0.000

The design parameters in table 5 are the coefficients of higher order terms of the surface type of the corresponding row of aspheric surfaces in table 4 according to the aspheric surface formula.

The optical path layout of the optical imaging module in the second embodiment is shown in fig. 7A, where TTL =13.362mm, and the image height IH =23.35mm. Fig. 7B shows an MTF graph of the optical imaging module in the second embodiment. From the MTF plot of the second embodiment, it can be seen that the average ordinate (modulation transfer function) value of each field is greater than the abscissa (spatial frequency per mm) value of 0.3. Fig. 7C shows a field curvature and a distortion diagram of the optical imaging module in the second embodiment, in which it is known that the field curvature is controlled in the range of (-0.1mm, 0.1mm) and the distortion is controlled in the range of (-33.87%, 0).

TABLE 6

Screen size C (inch)	1.3
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	4K＊4K
		Thickness of optical system (mm)	13.362
Angle of view FOV (°)	100
		Semi-transmitting semi-reflecting focal length f12	2.092F
eye box-eye movement range	7
		Focal length of system F (mm)	14.92
eye relief-eye distance (mm)	9
		F # -aperture	2.14
Optical outside diameter D (mm)	38
		Distortion Dst of system	-33.87％
Focal length f4 of cemented lens	11.6F

As can be seen from table 6, the optical system is a 3-piece structure by the relevant parameter design of tables 4 and 5; the focal length of the cemented lens group is 11.6F, the effective focal length of the semi-transmitting semi-reflecting surface in the cemented lens group (102, 103) is 2.092F, the thickness of the optical system is 13.362mm, the system focal length of 14.92mm can be obtained, and further, the large field angle of 100 degrees can be obtained; by designing the aperture arranged in front of the short-distance optical amplification module to be 2.14, namely, the corresponding aperture diameter D is 7mm, a large eye movement range of 7mm can be correspondingly obtained.

The design screen size is 1.3 inches, the eye distance is 9mm, and by combining the MTF graph of the second embodiment, it can be obtained that the average ordinate (modulation transfer function) of each field of view is higher than the abscissa (spatial frequency per millimeter) value of 0.37, and further, the view angle resolving power of the short-distance optical amplification module can support the resolution of 4000 × 4000, the distortion rate in the field curvature and distortion graph of the second embodiment is controlled within the range of (-33.87%, 0), and the field curvature and distortion graph of the second embodiment is controlled within the range of (-0.1mm, 0.1mm).

EXAMPLE III

The optical imaging module of the third embodiment is similar to that of fig. 5, but a fourth lens 308 is added between the human eye and the reflective polarizer 106. In the short-distance optical magnification module, the focal length F12 of the reflection surface containing the semi-transparent and semi-reflective surface in the cemented lens (102, 103) is equal to the focal length 2.066F of the system, and the concrete design data of the cemented lens group, the third lens 207 and other structures are as shown in the data of the following table 7 and table 8.

TABLE 7

Surf	Type	Radius	Thichness	Glass	Diameter	Conic
							OBJ	STANDARD	Infinity	Infinity		Infinity		0
2	PARAXIAL	Infinity		0		7									0
							STO	STANDARD	Infinity	9.000		7	0
4	STANDARD	200.00	1.50	PMMA	40
							5	STANDARD	130.00	2.00		40
6	STANDARD	Infinity	0.300	BK7	40	0
							7	STANDARD	Infinity	2.732	PMMA	40	0
8	EVEN ASPHERIC	-110.386	0.131		40	20.713
							9	EVEN ASPHERIC	98.325	6.062	PMMA	40	10.000
10	EVEN ASPHERIC	-62.268	-6.062	MIRROR	40	2.400
							11	EVEN ASPHERIC	98.325	-0.131		40	10.000
12	EVEN ASPHERIC	-110.386	-2.732	PMMA	40	20.713
							13	STANDARD	Infinity	-0.300	BK7	40	0.000
14	STANDARD	Infinity	0.300	MIRROR	40	0.000
							15	STANDARD	Infinity	2.732	PMMA	40	0.000
16	EVEN ASPHERIC	-110.386	0.131		40	20.713
							17	EVEN ASPHERIC	98.325	6.062	PMMA	40	10.000
18	EVEN ASPHERIC	-62.268	3.237	H-ZF6	40	2.400
							19	EVEN ASPHERIC	-162.296	0.500		40	-1.300
20	STANDARD	Infinity	0.400	BK7	40	0.000
							Image	STANDARD	Infinity			24	0.000

The seventh table analyzes the light broadcasting direction from the optical design angle, and the first line of the OBJ represents the relevant design parameters of the object plane; the second row is PARAXIAL surface paramaxial design data; the third row STO represents the diaphragm design parameter of the optical system, and the aperture is 7mm; the fourth and fifth rows are design data of the newly added fourth lens 308, and the material is PMMA; the sixth line represents the design parameters of a diaphragm formed by a reflection type polaroid and a second phase retarder in the optical module, wherein the type of the diaphragm is a STANDARD STANDARD surface, the material is BK7, and the diameter is 40mm; the seventh and eighth lines represent the design parameters of the third lens 207 (the seventh line is plane Radius = infinity, the surface type is a standard surface, the eighth line is an even aspheric surface, the material is PMMA, the diameter is 40mm; the ninth and tenth lines are the design data of the second lens 103 in the cemented lens (102, 103), the surface types are all aspheric surfaces, the material is PMMA, the diameter is 40mm; the tenth to sixteenth lines represent the reflection and transmission related design data of the light in the reflective polarizer and the second phase retarder, the third lens 207, and the second lens 103 in the cemented lens (102, 103) are not repeated here, the seventeenth to nineteenth lines are the design data of the cemented lens (102, 103), the surface types are all non-designed surfaces, the material is PMMA and H-ZF6 respectively, (the tenth and tenth line of the eighth line in the first line is the same as the surface type data, the surface type of the tenth line is the same as the surface type data of the H-ZF6, the twenty-th line is the design data of the semi-reflective glass, the twenty-transmissive glass design data is the second line is the standard surface type of the LCD, and the twenty-transmissive glass surface type is the standard surface data.

TABLE 8

Surf	Type	Conic	2 order item	Item of order 4	Item of order 6	Term of order 8	Term of order 10	12 th order term	14 th order term	Term of order 16
											OBJ	STANDARD		0
	PARAXIAL	0
											STO	STANDARD		0
4	STANDARD
												STANDARD
6	STANDARD	0
											7	STANDARD	0
8	EVEN ASPHERIC	20.713	0	-6.17E-06	6.20E-08	-5.76E-11	-1.01E-13	7.04E-17	0.0	0.0
											9	EVEN ASPHERIC	10.000	0	-1.72E-05	3.64E-08	-2.74E-11	-1.13E-14	2.20E-17	0.0	0.0
10	EVEN ASHERIC	2.400	0	2.17E-06	-1.09E-08	2.00E-11	-7.44E-15	8.47E-18	0.0	0.0
											11	EVEN ASHERIC	10.000	0	-1.72E-05	3.64E-08	-6.74E-11	-1.13E-14	2.20E-17	0.0	0.0
12	EVEN ASPHERIC	20.713	0	-6.17E-06	6.20E-08	-5.76E-I1	-1.01E-13	7.04E-17	0.0	0.0
											13	STANDARD	0.000
14	STANDARD	0.000
											15	STANDARD	0.000
16	EVEN ASHERIC	20.713	0	-6.17E-06	6.20E-08	-5.76E-11	-1.01E-13	7.04E-17	0	0
											17	EVEN ASPHERIC	10.000	0	-1.72E-05	3.64E-08	-2.74E-11	-1.13E-14	2.20E-17	0	0
18	EVEN ASPHERIC	2.400	0	2.17E-06	-1.09E-08	2.00E-11	-7.44E-15	8.47E-18	0	0
											19	EVEN ASPHERIC	-1.300	0	-2.35E-05	-1.16E-07	5.22E-10	5.24E-13	-3.41E-15	0	0
20	STANDARD	0.000
											Image	STANDARD	0.000

The Even aspheric surface (Even ASPHERE) formula is generally shown as follows:

wherein: r is the distance from the point on the lens to the optical axis, c is the curvature of the apex of the curved surface, K is the conic coefficient, a1, a2, a3,

a4 And a5, a6 and a7 are 2, 4, 6, 8, 10, 12, 14 and 16 sub-surface coefficients respectively.

For example table fifth eighth row 8:

C＝-1/110.386，K＝20.713，a1＝0，a2＝-6.17*10-6，a3＝6.2*10-8，a4＝-5.7 6*10-11，a5＝-1.0207*10-13，a6＝7.04*10-17，a7＝a8＝0.

substituting the above coefficients into formula Z is an aspheric expression of the second surface of the third lens 207, and so on.

The optical path layout of the optical imaging module in the third embodiment is shown in fig. 8A, where TTL = i7.30mm, and the image height IH =24mm. Fig. 8B shows an MTF graph of an optical imaging module in the third embodiment. Fig. 8C shows the field curvature and distortion diagram of the optical imaging module in the third embodiment, and it can be seen that the field curvature is controlled within the range of (-0.5 mm,0.5 mm) and the distortion is controlled within the range of (-33.56%, 0).

Other parameters corresponding to the short-range optical amplification module are shown in table 9.

TABLE 9

Screen size C (inch)	l.4
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	4K＊4K
		Thickness of optical system (mm)	17.3
Angle of view FOV (°)	100
		Semi-transmitting semi-reflecting focal length f12	2.066F
eye box-eye movement range	7
		Focal length of system F (mm)	15.072
eye relief-eye distance (mm)	9
		F # -aperture	2.15
Optical outside diameter D (mm)	40
		System distortion Dst	-33.56％
Focal length f4 of cemented lens	11.1F

The data in table 9 are indices for the design of the embodiment through the relevant parameters in tables 7 and 8, the optical system being a 4-piece structure; the focal length of the cemented lens is 11.1F, meanwhile, the effective focal length of the semi-transmitting surface reflecting surface in the cemented lens (102, 103) is 2.066F, and the thickness of the optical system is 17.3mm, so that the system focal length of 15.072mm can be obtained, and further a large field angle of 100 degrees can be obtained; by designing the aperture arranged in front of the short-distance optical amplification module to be 2.15, namely, the corresponding aperture diameter D is 7mm, a large eye movement range of 7mm can be correspondingly obtained.

The design screen size is 1.4 inches, the contact distance is 9mm, and the view angle resolving power of the short-distance optical magnification module can support 4000 × 4000 resolution by combining the three-MTF graphs of the embodiment of the figure, the distortion rate in the three-field curvature and distortion graph of the embodiment of the figure is controlled within the range of (-33.56%, 0), and the field curvature in the three-field curvature and distortion graph of the embodiment of the figure is controlled within the range of (-0.5 mm,0.5 mm).

Example four

The optical imaging module in the fourth embodiment is similar to fig. 5, in which a fourth lens 308 is added between the cemented lens and the first phase retarder (and the first phase retarder is integrated with the screen), in the short-distance optical zoom module, the focal length F12 of the reflective surface including the half-mirror in the cemented lens (102, 103) is designed to be equal to the system focal length 2.1F, and the cemented lens is (102, 103), the third lens 207, and other specific design data of the structure are as shown in table 10 and table 11 below.

TABLE 10

Surf	Type	Radius	Thichness	Glass	Diameter	Conic
							OBJ	STANDARD	Infinity	Infinity		Infinity		0
2	PARAXIAL	Infinity		0		7									0
							STO	STANDARD	Infinity	11.000		7	0
4	STANDARD	Infinity	0.300	BK7	38.000	0
							5	STANDARD	Infinity	1.300	N-LAK7	38.000	0
6	EVEN ASPHERIC	204.140	1.166		38.000	30.020
							7	EVEN ASPHERIC	63.625	5.556	K11	38.000	3.102
8	EVEN ASPHERIC	-53.044	-5.556	MIRROR	38.000	9.148
							9	EVEN ASPHERIC	63.625	-1.166		38.000	3.102
10	EVEN ASPHERIC	204.140	-1.300	N-LAK7	38.000	30.020
							11	STANDARD	Infinity	-0.300	BK7	38.000	0.000
12	STANDARD	Infinity	0.300	MIRROR	38.000	0.000
							13	STANDARD	Infinity	1.300	N-LAK7	38.000	0.000
14	EVEN ASPHERIC	204.140	1.166		38.000	30.020
							15	EVEN ASPHERIC	63.625	5.556	K11	38.000	3.102
16	EVEN ASPHERIC	-53.044	3.000	H-ZF6	38.000	9.148
							17	EVEN ASPHERIC	-155.376	1.744		38.000	-10.046
18	STANDARD	-343.571	2.000	PMMA		0.000
							19	STANDARD	-208.925	1.000			0.000
20	STANDARD	Infinity	0.400	BK7	40	0.000
							Image	STANDARD	Infinity			24	0.000

The seventh table analyzes the light broadcasting direction from the optical design angle, and the first line OBJ represents the relevant design parameters of the object plane; the second row is PARAXIAL surface paramaxial design data; the third row STO represents the diaphragm design parameter of the optical system, and the aperture is 7mm; the fourth row represents the design parameters of a diaphragm formed by the reflection type polaroid and the second phase retarder in the optical module, the type of the diaphragm is a STANDARD STANDARD surface, the material is BK7, and the diameter is 38mm; the fifth line and the sixth line represent design parameters of the third lens 207 (the seventh line is plane Radius = infinity, the surface type is a standard surface, the sixth line is an even aspheric surface, the material is N-LAK7, the diameter is 38mm, the seventh line and the eighth line refer to design data of the second lens 103 in the cemented lens (102, 103), the surface types are all aspheric surfaces, the material is K11, the diameter is 38mm, the eighth line to the fourteen lines represent reflection-transmission-related design data of light rays in the reflective polarizer, the second phase retarder, the third lens 207 and the second lens 103 in the cemented lens (102, 103) are not consistent, the fifteenth line to the seventeenth line are cemented lens (102, 103) design data, the surface types are all non-surface, the material is K11 and H-ZF6, the surface type of the sixteenth line and the eighth line in the table are the same, the semi-reflective function is achieved, the semi-reflective protection surface design data is the twenty-ninth line is PMMA, the twenty-eighth line is a semi-transparent glass design data, and the twenty-transparent glass design data is a twenty-transparent glass design data.

TABLE 11

The Even aspheric surface (Even ASPHERE) formula is generally shown as follows:

wherein: r is the distance from the point on the lens to the optical axis, c is the curvature of the apex of the curved surface, K is the conic coefficient, a1, a2, a3,

a4 And a5, a6 and a7 are 2, 4, 6, 8, 10, 12, 14 and 16 sub-surface coefficients respectively.

For example table seventh sixth row 6:

C＝1/204.14，K＝30.02，a1＝0，a2＝-1.07*10-5，a3＝4.29*10-8，a4＝-6.62* 10-11，a5＝-6.91*10-14，a6＝4.68*10-16，a7＝a8＝0.

substituting the above coefficients into formula Z is an aspheric expression of the second surface of the third lens 207, and so on.

The optical path layout of the optical imaging module in the fourth embodiment is shown in fig. 9A, where TTL =16.47mm, and the image height IH =24mm. Fig. 9B shows an MTF graph of the optical imaging module according to the fourth embodiment, and it can be known that an average ordinate (modulation transfer function) value of each field is greater than an abscissa (spatial frequency per millimeter) value of 0.2. FIG. 9C shows the field curvature and distortion diagram of the optical imaging module of the fourth embodiment, and it can be seen from the field curvature and distortion diagram of the fourth embodiment that the field curvature is controlled within the range of (-0.2mm, 0.2mm) and the distortion is controlled within the range of (-30.86%, 0).

TABLE 12

Screen size C (inch)	1.4
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	4000＊4000
		Thickness of optical system (mm)	16.47
Angle of view FOV (°)	100
		Semi-transmitting semi-reflecting focal length f12	2.1F
eye box-eye movement range	7
		Focal length of system F (mm)	17.36
eye relief-eye distance (mm)	11
		F # -aperture	2.48
Optical outside diameter D (mm)	40
		Distortion Dst of system	-30.86％
Focal length f4 of cemented lens	4.95F

Table 12 data are indices for the embodiment designed through the relevant parameters in tables 10 and 11, the optical system is a 4-piece structure; the focal length of the cemented lens is 4.95F, the effective focal length of the semi-transmitting semi-reflecting surface in the cemented lens (102, 103) is 2.1F, the thickness of the optical system is 16.47mm, the system focal length of 17.36mm can be obtained, and further the large field angle of 100 degrees can be obtained; by designing the aperture arranged in front of the short-distance optical amplification module to be 2.48, namely, the corresponding aperture diameter D is 7mm, a large eye movement range of 7mm can be correspondingly obtained.

The design screen size is 1.4 inches, the contact distance is 11mm, and by combining the MTF graph of the fourth embodiment, it is further found that the viewing angle resolving power of the short-distance optical magnification module can support the resolution of 4000 × 4000, the distortion rate in the field curvature and distortion graph of the fourth embodiment is controlled within the range of (-30.86%, 0), and the field curvature and distortion graph of the fourth embodiment is controlled within the range of (-0.5 mm,0.5 mm).

EXAMPLE five

The optical assembly of the fifth embodiment is similar to that of fig. 5, but a fourth lens 308 is added between the cemented lens (102, 103) and the third lens 207, in the short-distance optical magnification module, the focal length F12 of the reflection surface including the half-mirror in the cemented lens (102, 103) is designed to be equal to the system focal length 2.13F, and the cemented lens (102, 103), the third lens 207 and other structure specific design data are as shown in table 13 and table 14 below.

Watch 13

The table 13 analyzes the light propagation direction from the optical design angle, and the first row OBJ represents the object plane related design parameters; the second row STO represents the diaphragm design parameter of the optical system, the surface type is a paraxial surface, and the aperture is 7mm; the third row represents the design parameters of a diaphragm formed by a reflection type polarizer and a second phase retarder in the optical module, and the diaphragm is of a STANDARD STANDARD surface, made of BK7 and 40mm in diameter; the fourth and fifth rows represent the design parameters of the third lens 207 (the fourth row is plane Radius = infinity, the surface type is a standard surface, the fifth row is an even aspheric surface, the material is PMMA, the diameter is 40mm, the sixth to seventh rows are the design data of the newly added fourth lens 308, the surface types are all aspheric surfaces, the material is PMMA, the eighth and ninth rows are the design data of the second lens 103 in the cemented lens (102, 103), the surface types are all aspheric surfaces, the material is K11, the diameter is 40mm, the ninth to nineteenth rows represent the design data of the reflection and transmission of the light in the reflective polarizer and the second phase retarder, the newly added lens 308, the second lens 103 in the cemented lens (102, 103) are not repeated, the twenty-second row is the cemented lens (102, 103) design data, the surface types are all the non-solved surface, the material is K11 and the H-LAK, the twenty-first row is the design data of the cemented lens (102, the twenty-second row is the design data of the semi-transparent glass surface, the twenty-third row is the same as the third lens 207 design data, the twenty-second row is the semi-transparent glass surface type, and the third row is the semi-transparent glass surface type, the third LCD screen is the same as the semi-transparent glass screen, and the twenty-transparent glass screen.

TABLE 14

Surf	Type	Conic	Term of order 2	Item of 4 th order	Term of order 6	Term of order 8	Term of order 10	Term of 12 th order	14 th order term	16 th order term
											OBJ	STANDARD	0
STO	PARAXIAL	0
											3	STANDARD	0
4	STANDARD	0
											5	EVEN ASPHERIC	-6.021	0	-1.13E-05	3.83E-08	-5.12E-11	-4.38E-15	2.57E-16	0	0
6	EVEN ASPHERIC	-110.366
											7	EVEN ASPHERIC	71.733
8	EVEN ASPHERIC	4.592	0	-2.24E-05	2.33E-08	-2.64E-11	4.61E-14	-7.10E-17	0	0
											9	EVEN ASPHERIC	9.958	0	-1.28E-08	-4.89E-09	2.41E-11	-3.74E-14	1.94E-17	0	0
10	EVEN ASPHERIC	4.592	0	-2.24E-05	2.33E-08	-2.64E-11	4.61E-14	-7.10E-17	0	0
											11	EVEN ASPHERIC	71.733
12	EVEN ASPHERIC	-110.366
											13	EVEN ASPHERIC	-6.021	0	-1.13E-05	3.83E-08	-5.12E-11	-4.38E-15	2.57E-16	0	0
14	STANDARD	0.000
											15	STANDARD	0.000
16	STANDARD	0.000
											17	EVEN ASPHERIC	-6.021	0	-1.13E-05	3.83E-08	-5.12E-11	-4.38E-15	2.57E-16	0	0
18	EVEN ASPHERIC	-110.366
											19	EVEN ASPHERIC	71.733
20	EVEN ASPHERIC	4.592	0	-2.24E-05	2.33E-08	-2.64E-11	4.61E-14	-7.10E-17	0	0
											21	EVEN ASPHERIC	9.958	0	-1.28E-08	-4.89E-09	2.41E-11	-3.74E-14	1.94E-17	0	0
22	EVEN ASPHERIC	4.722	0	-4.65E-05	4.67E-08	2.39E-10	-1.09E-12	1.23E-15	0	0
											23	STANDARD	0.000
Image	STANDARD	0

The Even aspheric surface (Even ASPHERE) formula is generally shown as follows:

wherein: r is the distance from the point on the lens to the optical axis, c is the curvature of the apex of the curved surface, K is the conic coefficient, a1, a2, a3,

a4 And a5, a6 and a7 are 2, 4, 6, 8, 10, 12, 14 and 16 sub-surface coefficients respectively.

For example, table 14, row 5, plane 5:

C＝-1/275.499，K＝-6.021，a1＝0，a2＝-1.13*10-5，a3＝3.83*10-8，a4＝-5. 12*10-11，a5＝-4.38*10-15，a6＝2.57*10-16，a7＝a8＝0.

substituting the above coefficients into formula Z is an aspheric expression of the second surface of the third lens 207, and so on.

The optical path layout of the optical imaging module in the fifth embodiment is shown in fig. 10A, where TTL =16.5mm and the image height IH =27mm. Fig. 10B shows MTF plots of the optical imaging module of the fifth embodiment, and it can be seen that the average ordinate (modulation transfer function) value of each field of view is greater than the abscissa (spatial frequency per mm) value of 0.2. Fig. 10C shows the field curvature and distortion diagram of the optical imaging module in example five, and it can be seen that the field curvature is controlled in the range of (-0.2 mm,0.2 mm), and the distortion is controlled in the range of (-28.55%, 0).

Watch 15

Screen size C (inch)	1.5
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	3000＊3000
		Thickness of optical system (mm)	16.5
Angle of view FOV (°)	100
		Semi-transmitting semi-reflecting focal length f12	2.13F
eyebox-eye movement range	7
		Focal length of system F (mm)	20.51
eye relief-eye distance (mm)	11
		F # -aperture	2.93
Optical outside diameter D (mm)	40
		System distortion Dst	-28.55％
Focal length f4 of cemented lens	7.34F

The data of table 15 are indices designed by the relevant parameters in tables 13 and 14 for example five, the optical system is a 4-piece structure; the focal length of the cemented lens is 7.34F, the effective focal length of the semi-transmitting semi-reflecting surface in the cemented lens (102, 103) is 2.13F, the thickness of the optical system is 16.5mm, the system focal length of 20.51mm can be obtained, and further the large field angle of 100 degrees can be obtained; by designing the aperture arranged in front of the short-distance optical amplification module to be 2.93, namely, the corresponding aperture diameter D is 7mm, a large eye movement range of 7mm can be obtained correspondingly.

The design screen size is 1.5 inches, the eye distance is 11mm, and the view angle resolving power of the short-distance optical amplification module can support 3000 × 3000 resolution by combining the five-MTF diagram of the embodiment, the distortion rate in the five-field curvature and distortion diagram of the embodiment is controlled within the range of (-28.55%, 0), and the field curvature in the five-field curvature and distortion diagram of the embodiment is controlled within the range of (-0.2mm, 0.2mm).

EXAMPLE six

The optical imaging structure of the sixth embodiment is substantially the same as that shown in fig. 3 (fig. 4). In the short-distance optical magnification module with this structure, the focal length F12 of the reflection surface including the half-mirror surface in the cemented lens (102, 103) is designed to be equal to the system focal length 2.071F, the cemented lens (102, 103), and the specific design data of the third lens 207 are as shown in table 16 and table 17 below.

TABLE 16

Surf	Type	Radius	Thichness	Glass	Diameter	Conic
							OBJ	STANDARD	Infinity	Infinity			0
2	PARAXIAL	Infinity	9		7
							STO	EVEN ASPHERIC	151.008	2.872	PMMA	40	20.53
4	STANDARD	Infinity	0.300	BK7	40	0
							5	STANDARD	Infinity	2.000		40	0
6	EVEN ASPHERIC	92.905	5.430	PMMA	40	-0.39
							7	EVEN ASPHERIC	-61.404	-5.430	MIRROR	40	3.15
8	EVEN ASPHERIC	92.905	-2.000		40	-0.39
							9	STANDARD	Infinity	-0.300	BK7	40	0.00
10	STANDARD	Infinity	0.300	MIRROR	40	0.00
							11	STANDARD	Infinity	2.000		40	0.00
12	EVEN ASPHERIC	92.905	5.430	PMMA	40	-0.39
							13	EVEN ASPHERIC	-61.404	3.000	PMMA	40	3.15
14	EVEN ASPHERIC	-98.834	0.500		40	8.09
							15	STANDARD	Infinity	0.400	BK7	24	0.00
Image	STANDARD	Infinity	0.000		24	0.00

The table 16 analyzes the light broadcasting direction from the optical design angle, the first row of OBJ represents the object plane related design parameters, the second row of PARAXIAL plane paramaxial design data, and the aperture is 7mm; the third row is used as a system diaphragm surface and is also a front surface of the third lens, so the third row and the fourth row represent design data of the third lens 207 (the fourth row is a plane Radius = infinity and is a standard surface, the third row is an even aspheric surface, is made of PMMA, and has a diameter of 40 mm); the fourth line to the fifth line represent the design parameters of a diaphragm formed by a reflection type polaroid and a second phase retarder in the optical module, wherein the diaphragm is a STANDARD STANDARD surface, is made of BK7 and has a diameter of 40mm; the sixth row and the seventh row refer to the design data of the second lens 103 in the cemented lens (102, 103), the surface type is all aspheric, the material is PMMA, and the diameter is 40mm; the seventh to eleventh rows represent the reflection and transmission related design data of the light rays in the reflective polarizer, the second phase retarder and the second lens 103 in the cemented lens (102, 103), and the twelfth to fourteenth rows are the design data of the cemented lens (102, 103), and the surface types are all non-surface-requiring and are made of PMMA, and the surface type of the thirteenth row and the surface type of the seventh row in the table are the same, so as to realize the semi-transparent and semi-reflective function; the fifteenth row is the design data of the cover glass of the LCD screen, the surface type is a standard surface, and the material is BK7; and the sixteenth row is the image plane.

TABLE 17

The Even aspheric surface (Even ASPHERE) formula is generally shown as follows:

wherein: r is the distance from the point on the lens to the optical axis, c is the curvature of the apex of the curved surface, K is the conic coefficient, a1, a2, a3,

a4 And a5, a6 and a7 are 2, 4, 6, 8, 10, 12, 14 and 16 sub-surface coefficients respectively.

For example table eleven row 3 face 3:

C＝1/151，K＝20.53，a1＝0，a2＝-2.99*10-6，a3＝4.32*10-8，a4＝-1.42*10- 10，a5＝-3.94*10-13，a6＝8.78*10-16，a7＝a8＝0.

substituting the above coefficients into formula Z is an aspheric expression of the second surface of the third lens 207, and so on.

The optical path layout of the optical imaging module in the sixth embodiment is shown in fig. 11A, where TTL =14.5mm and the image height IH =24mm. Fig. 11B shows an MTF graph of an optical imaging module according to the sixth embodiment, and it can be seen that an average ordinate (modulation transfer function) value of each field is greater than an abscissa (spatial frequency per millimeter) value of 0.1. FIG. 11C shows the field curvature and distortion diagram of the optical imaging module of the sixth embodiment, and it can be seen that the field curvature is controlled within the range of (-0.2mm, 0.2mm) and the distortion is controlled within the range of (-28.55%, 0).

Watch 18

Screen size C (inch)	1.4
		Wavelength range (nm)	470-700
Monocular screen resolution (pixel)	4000＊4000
		Thickness of optical system (mm)	14.5
Angle of view FOV (°)	100
		Semi-transmitting semi-reflecting focal length f12	2.071F
eye box-eye movement range	7
		Focal length of system F (mm)	14.824
eye relief-eye distance (mm)	9
		F # -aperture	2.12
Optical outside diameter D (mm)	40
		System distortion Dst	-34.31％
Focal length f4 of cemented lens	4.9F

The data of table 18 are indices designed by the relevant parameters in tables 16 and 17 in example six, and the optical system is a 3-piece structure; the focal length of the cemented lens is 4.9F, the effective focal length of the semi-transmitting semi-reflecting surface in the cemented lens (102, 103) is 2.071F, the thickness of the optical system is 14.5mm, the system focal length of 14.824mm can be obtained, and further the large field angle of 100 degrees can be obtained; through setting up the diaphragm design in the front of short distance optical amplification module 2.12, corresponding diaphragm diameter D is 7mm promptly, corresponding can obtain 7 mm's big eye movement scope.

The designed screen size is 1.4 inches, the contact distance is 9mm, and the MTF graph of the sixth embodiment of the present invention is combined to find that the viewing angle resolving power of the short-distance optical magnification module can support 4000 × 4000 resolution, the distortion rate in the field curvature and distortion graph of the sixth embodiment of the present invention is controlled within a range of (-34.31%, 0), and the field curvature in the field curvature and distortion graph of the sixth embodiment of the present invention is controlled within a range of (-0.2 mm,0.2 mm).

Therefore, by using the short-distance optical amplification module provided by the embodiment, an ultrathin VR wearable device with a large field angle, a large eye movement range and a high-quality imaging effect can be manufactured.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (11)

1. The optical imaging module, characterized in that, the optical imaging module includes:

the first lens is close to the object side of the optical imaging module;

a second lens on an image side of the first lens, wherein the second lens is cemented with the first lens to form a cemented lens;

a transflective layer located at a position of the glue between the first lens and the second lens;

a second phase retarder on an image side of the second lens; and

a reflective polarizer disposed on an image side of the second phase retarder.

2. The optical imaging module of claim 1 further comprising a first retarder disposed on a side of the first lens proximate the object side.

3. The optical imaging module of claim 2 wherein the first and second phase retarders are quarter-wave plates, the optical axes of the first and second phase retarders are orthogonally disposed, and the first phase retarder is a separate component or is integrated with the display screen.

4. The optical imaging module of any of claims 1-3 wherein the first and second lenses conform to one of:

the surface of the image side of the first lens is concave; the object side surface of the second lens is convex;

the surface of the image side of the first lens is convex; the object side surface of the second lens is concave;

wherein the semi-transparent semi-reflecting layer has a contour which is consistent with the image side surface of the first lens and the object side surface of the second lens.

5. The optical imaging module of any of claims 1-3 wherein the first lens has a positive or negative optical power and the cemented lens has a positive optical power.

6. The optical imaging module of any of claims 1-3 further comprising a third lens positioned between the second phase retarder and the second lens or on an image side of the reflective polarizer.

7. The optical imaging module of claim 6, wherein the third lens element has a positive power or a negative power, and an object-side surface or an image-side surface of the third lens element is planar or non-planar.

8. The optical imaging module of claim 7 wherein the second phase retarder and the reflective polarizer are sequentially attached to the planar or non-planar surface.

9. The optical imaging module of any of claims 1-3, wherein the transflective layer has a focal length of reflection F12, and the optical imaging module has a focal length of F, satisfying the following relationship: f12 is more than or equal to 1.1F and less than or equal to 4F.

10. The optical imaging module of claim 6 further comprising a fourth lens;

wherein the fourth lens is positioned on the object side of the first lens; or

The fourth lens is positioned between the second lens and a third lens, and the third lens is positioned on the object side of a second phase retarder; or

The fourth lens is positioned between the second lens and a second phase retarder, and the third lens is positioned on the image side of the reflective polarizer; or

The fourth lens is positioned on the image side of the reflective polarizer, and the third lens is positioned on the object side of the second phase retardation plate; or alternatively

The fourth lens is positioned on the image side of the third lens, and the third lens is positioned on the image side of the reflective polarizer.

11. A near-eye display device comprising:

a display screen; and

it is characterized by also comprising: the optical imaging module of any of claims 1-10, disposed in the optical path downstream of the display screen.

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