CN110824710A

CN110824710A - Near-to-eye perspective head display optical system

Info

Publication number: CN110824710A
Application number: CN201911101919.9A
Authority: CN
Inventors: 房晓俊
Original assignee: Taap Yi Hai (shanghai) Technology Co Ltd
Current assignee: Taap Yi Hai (shanghai) Technology Co Ltd
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2020-02-21
Anticipated expiration: 2039-11-12
Also published as: CN110824710B

Abstract

The invention relates to a near-eye perspective head display optical system, in particular to a near-eye perspective head display optical system capable of improving a longitudinal view field angle, which comprises a first lens, a second lens and an image display; one side of the first lens is attached to one side of the image display, one side of the second lens is attached to the other side of the image display, the other side of the first lens is attached to the other side of the second lens, and the first lens, the second lens and the image display are distributed to form a triangle-like space; the image display is characterized by being formed by splicing at least two display units. Has the advantages that: the image display spliced by at least two display units can improve the longitudinal view field angle, enhance the user experience, and ensure that the FOV parameter can reach 110-120 degrees or even higher on the whole, so that a more vivid virtual-real combination effect can be obtained, the improvement of the virtual-real combination effect increases the immersion and reality, and the development and application of an augmented reality technology are promoted.

Description

Near-to-eye perspective head display optical system

Technical Field

The invention relates to a near-eye perspective head display optical system, in particular to a near-eye perspective head display optical system capable of improving a longitudinal view field angle.

Background

At present, Augmented Reality (AR for short) head-mounted displays are rapidly developed, in order to achieve immersion and a large viewing angle, the viewing angle of an AR head-mounted display product is small, the AR head-mounted display product has the same size as the AR head-mounted display product and is large in lens thickness, and because the viewing angle, the exit pupil aperture and the focal length of an optical system are in a mutually restricted relationship, the large viewing angle is achieved at the same time, and the large exit pupil aperture and the short focal length are quite difficult.

The present invention, CN201810050821.4, provides a near-eye see-through head-display optical system, which includes a first lens, a second lens and a miniature image display, wherein the first lens and the second lens are both attached to the miniature image display, and the first lens and the second lens are both of uniform-thickness free-form surface lenses. By the optical system structure of the near-eye perspective head display provided by the invention, the times of light refraction in the optical system structure can be reduced, and the aberration of light emitted by the miniature image display in each direction can be eliminated, so that the image can not be subjected to aberration when the miniature image display is seen in each direction and angle.

The FOV (visual angle) of the near-eye perspective head display optical system can reach about 100.8 degrees, but has a certain distance compared with the common FOV physiological parameters of 120-150 degrees of human (eyes). In the technical development of the AR glasses optical path of each company, the FOV is the technical parameter which is increased as much as possible. Because only the FOV parameter is coincident with the general FOV physiological parameter (as much as possible) of human (eyes), a more realistic virtual-real combination effect can be obtained, and the virtual-real combination effect can directly promote the development and application of the augmented reality technology.

Disclosure of Invention

In view of the above problems in the prior art, a near-eye see-through head-display optical system is provided.

The specific technical scheme is as follows:

the invention discloses a near-eye perspective head display optical system, which comprises a first lens, a second lens and an image display; one side of the first lens is attached to one side of the image display, one side of the second lens is attached to the other side of the image display, the other side of the first lens is attached to the other side of the second lens, and the first lens, the second lens and the image display are distributed to form a triangle-like space; the image display is formed by splicing at least two display units.

The invention provides a method for splitting an FOV of a near-eye perspective head-display optical system in a patent CN201810050821.4 into a transverse FOV and a longitudinal FOV, wherein the splitting aims to improve the FOV in any dimension of a certain transverse dimension/longitudinal dimension, namely the FOV parameter can be improved on the whole. The invention, however, creates a new solution for increasing the FOV in the longitudinal direction.

Preferably, the plurality of display units are spliced in a stepped parallel staggered arrangement.

Preferably, the polylith the display element all with length, with width, with thickness, polylith the fixed setting of display element is in the ladder tooth department of ladder-shaped rubdown piece, perhaps, the polylith the side of display element passes through the fixed formation ladder-shaped arrangement concatenation of fixed connection structure.

Preferably, the plurality of display units are different in length, and the plurality of display units different in length are aligned on one side in the length direction and arranged in the length order.

Preferably, the non-blocked part of the plurality of display units is a display area.

Preferably, a side of the plurality of display cells aligned in the longitudinal direction is attached to one side of the second lens; one side of the display unit with the longest length is attached to one side of the first lens.

Preferably, the plurality of display units have different widths, and the plurality of display units having different widths are aligned on one side in the width direction and arranged in the order of width.

Preferably, one side of the display unit with the narrowest width is attached to one side of the first lens, and the other side of the display unit with the narrowest width abuts against the other display units; one side of the display unit with the widest width is attached to one side of the second lens, and the other side of the display unit with the widest width is abutted against the other display units.

Preferably, every two adjacent display units are fixed through a fixing frame with a preset shape, or every two adjacent display units are bonded through fixing glue.

Preferably, the display unit is a frame-free spliced screen.

Preferably, the first lens and the second lens are both uniform-thickness free-form surface lenses, so that an image generated by the image display is reflected and imaged in the first lens and the second lens.

Preferably, the first lens has a first surface and a second surface, and the second lens has a third surface and a fourth surface.

Preferably, the first surface, the second surface, the third surface, and the fourth surface satisfy the following equation (1):

wherein c is 1/r0, r0 is the curvature radius of the free-form surface reference plane, k is the coefficient of the quadric surface, r is the radial coordinate of the incident ray, ai is the high order coefficient,

is a Zernike polynomial, N is the total number of Zernike polynomials, Ai is the coefficient of the ith Zernike polynomial, ρ is the normalized radial coordinate,

is a normalized angular coordinate.

Preferably, the second surface, the third surface and the fourth surface should satisfy conditional equations (2) to (4):

wherein b is an emission point of a first light ray emitted by the image display, b2 is an intersection point of the first light ray reflected with the third surface, and b1 is an intersection point of the first light ray reflected with the second surface; b3 is the intersection point of the first light ray and the third surface when the first light ray is refracted; a is an emission point at which the image display emits a second light ray, a2 is an intersection point with the third surface when the second light ray is reflected, and a1 is an intersection point with the second surface when the second light ray is reflected; a3 is the intersection point of the second light ray with the third surface when refracted.

Preferably, the second surface and the third surface should satisfy conditional equation (5),

wherein n' represents a refractive index of the first lens or the second lens.

Preferably, the second surface and the third surface are coated with a semi-reflective and semi-transparent film, so that an image generated by the image display is reflected and imaged in the first lens and the second lens.

Preferably, the first lens and the second lens are integrally formed.

Preferably, the reflectivity of the transflective film of the second surface is 20-70%, or the reflectivity of the transflective film of the third surface is 20-70%.

Preferably, the material of the first lens and the second lens is optical glass, methyl methacrylate, polycarbonate, polypropylene (PP), polyethylene terephthalate (PET) or Nylon (Nylon).

Preferably, the thickness of the first lens and the thickness of the second lens are both 1-3 mm.

Preferably, after the image generated by the image display is reflected by the first lens and the second lens, the image display enlarges the image in the Y-axis direction and enlarges the image in the X-axis direction on the reflection surface of the first lens, and enlarges the image in the Y-axis direction and reduces the image in the X-axis direction on the reflection surface of the second lens.

The technical scheme of the invention has the beneficial effects that: the near-eye perspective head display optical system is provided, the image display spliced by at least two display units can improve the longitudinal view field angle and enhance the user experience, the overall FOV parameter can reach 110-120 degrees and is even higher, so that a more vivid virtual-real combination effect can be obtained, the improvement of the virtual-real combination effect is improved, the immersion and the reality are increased, and the development and the application of an augmented reality technology are promoted.

Drawings

Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings. The drawings are, however, to be regarded as illustrative and explanatory only and are not restrictive of the scope of the invention.

FIG. 1a is a schematic diagram of a near-eye perspective head display optical system in the prior art;

FIG. 1b is a prior art optical path diagram of an embodiment of a near-eye perspective head-viewing optical system (where E refers to the eye);

FIG. 2 is a schematic cross-sectional view of a first embodiment of a near-eye see-through head-display optical system according to an embodiment of the invention;

FIG. 3 is a schematic cross-sectional view of a second embodiment of a near-eye see-through head-display optical system according to an embodiment of the invention;

FIG. 4 is a schematic cross-sectional view of an image display of a near-eye see-through head-display optical system according to a second embodiment of the invention;

FIG. 5 is a schematic cross-sectional view of an image display of a near-eye see-through head-display optical system according to a third embodiment of the invention;

FIG. 6 is a schematic cross-sectional view of an image display of a near-eye see-through head-display optical system according to a fourth embodiment of the invention;

FIG. 7 is a diagram of an optical path of a second embodiment of a near-eye see-through head-display optical system (where E refers to the eye) according to an embodiment of the present invention;

FIG. 8 is an optical path diagram of a second embodiment of a near-eye see-through head-display optical system according to a sixth embodiment of the present invention;

fig. 9 is another optical path diagram of a second embodiment of a near-eye see-through head-display optical system according to a seventh embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

The coordinate system referred to in the description and drawings of the specification is a cartesian coordinate system, i.e., a three-axis (X, Y, Z) orthogonal coordinate system, and a right-axis coordinate system, with the directions of the three axes being as indicated in the respective drawings of the specification. In the present invention, the axial direction of the X axis is referred to as a first direction, the axial direction of the Y axis is referred to as a second direction, and the axial direction of the Z axis is referred to as a third direction; a plane formed by the Y axis and the Z axis is referred to as a first plane, a plane formed by the X axis and the Y axis is referred to as a second plane, a plane formed by the X axis and the Z axis is referred to as a third plane, and the origin of coordinate axes is fixed to the intersection of the first lens and the second lens, as shown by reference numeral 0 in the drawings of the specification.

The first embodiment is as follows:

as shown in fig. 2, the present invention provides a near-eye see-through head-display optical system 1, which comprises a first lens 10, a second lens 11 and an image display 12; one side of the first lens 10 is attached to one side of the image display 12, one side of the second lens 11 is attached to the other side of the image display 12, the other side of the first lens 10 is attached to the other side of the second lens 11, and the first lens 10, the second lens 11 and the image display 12 surround to form a triangle-like space; the image display 12 is formed by splicing at least two display units 120.

Through the technical scheme of the near-eye perspective head display optical system, the near-eye perspective head display optical system 1 comprises a first lens 10, a second lens 11 and an image display 12, wherein the image display is spliced by at least two display units 120, the display units 120 are frame-free spliced screens, and the parts of the plurality of display units 120 which are not shielded are display areas. The plurality of display units 120 may be formed by a liquid crystal screen (e.g., LCD, OLED, AMOLED, or LED), an LCOS screen, or a CMOS screen. The total area of the projection/display screen formed by the plurality of display units 120 may be in the range of 5 inches to 7 inches, and preferably in the range of 1.5 inches to 3 inches, but the present invention is not limited thereto as long as the locked display units 120 can be seen to cover the open end formed by the first lens 10 and the second lens 11 on the parallel plane. The plurality of display units 120 further have preprocessing functions, such as software of the display units 120, for controlling the number of generated images and controlling the magnification of different pixels in the images, so that barrel distortion and keystone distortion seen by the retinas of the user's eyes are eliminated, and the present invention is not limited to these functions.

For example, as shown in fig. 2, two display units 120 may be selected, the longitudinal viewing angle of the image display 12 composed of two display units 120 is β, and as shown in fig. 3, three display units 120 may be selected, the longitudinal viewing angle of the image display 12 composed of three display units 120 is γ, and as can be seen from fig. 1a and 1b in the prior art, the longitudinal viewing angle of the image display 12 composed of one display unit 120 is α, in contrast, it is concluded that γ > β > α, that is, the image display 12 formed by splicing a plurality of display units 120 in a step-like parallel staggered arrangement is used, the splicing mode can improve the longitudinal viewing angle and enhance the user experience, and how many display units are spliced, which is not limited by the present invention.

Example two:

as shown in fig. 4, in a preferred embodiment, the plurality of display units 120 have the same length, the same width, and the same thickness, and the plurality of display units 120 are fixedly disposed at the step teeth of the stepped polishing block, or the side edges of the plurality of display units 120 are fixedly connected by a fixed connection structure to form a stepped arrangement.

The length, width, and thickness defined in this embodiment may be understood as the length, width, and height of a conventional cube, and the multi-block display unit 120 may be at least two, for example, two or three blocks, and the embodiment is described as a manner of splicing three display units 120, as shown in fig. 4, three display units 120 having the same length, the same width, and the same thickness are used, in the cross-sectional view of fig. 4, a lower portion of the display unit 120 close to the first lens 10 and facing the second lens 11 is attached to a point close to an upper portion of the display unit 120 close to the second lens 11 and facing the first lens 10, and the three display units 120 surround the first lens 10 and the second lens 11 to form a triangle-like space, and the light path diagram of the three display units 120 is shown in fig. 7. In the cross-sectional view of fig. 4, the three display units 120 are bonded to each other point-to-point, and in the schematic structural view, the three display units 120 are bonded to each other edge-to-edge.

The three display units 120 are fixed in two ways, the first way is that every two adjacent display units 120 can be fixed by a fixing frame with a preset shape, for example, a fixing frame with the same length, width and thickness as the display units 120 is selected to respectively fix the three display units 120; for example, the stepped fixing block is used as a fixing frame to fix the back of the display unit; for example, the ladder-type fixing frame is a fixing frame to fix two sides of the display unit; the fixing mode can be fixed by selecting the existing technology, and is not described in detail herein. The second way is that every two adjacent display units 120 are bonded by fixing glue, for example, the attached edge between every two adjacent display units 120 is bonded by fixing glue.

Furthermore, the splicing arrangement mode can improve the longitudinal view field angle and enhance the user experience.

Example three:

in a preferred embodiment, as shown in fig. 5, the plurality of display units 120 are different in length, and the plurality of display units 120 having different lengths are aligned at one side in the length direction and arranged in the order of length.

In the above-described embodiment, as a preferred embodiment, the plurality of display units 120 are attached to one side of the second lens 11 on the side aligned in the longitudinal direction; one side of the longest display unit 120 is attached to one side of the first lens 10.

The length, width and thickness defined in this embodiment may be understood as the length, width and height of a conventional cube, and a manner of splicing three display units 120 is described, where three display units 120 with different lengths, the same width and the same thickness are selected, in the cross-sectional view of fig. 5, the lengths of the display units 120 increase from bottom to top, and the other sides of the three display units 120 are flush with the end near the second lens 11, and the widths and thicknesses of two adjacent display units 120 are the same. The three display units 120 respectively surround the first lens 10 and the second lens 11 to form a triangle-like space. It should be noted that, in the cross-sectional view of fig. 5, three display units 120 are in edge-to-edge contact with each other, so that alignment and assembly are facilitated, in the structural schematic diagram, three display units 120 are in surface-to-surface contact with each other, and the display of the display unit 120 behind is blocked by the display unit 120 in front; or the blocked display unit 120 may not be used for display.

The fixing modes of the three display units 120 are divided into two types, the first mode is that every two adjacent display units 120 can be fixed by a fixing frame with a preset shape, for example, the fixing frame with the same width and the same thickness as the display units 120 and the length increasing from bottom to top is selected to respectively fix the three display units 120, and the fixing mode can be selected from the prior art to fix, which is not described herein again. The second way is that every two adjacent display units 120 are bonded by fixing glue, for example, the contact surface between every two adjacent display units 120 is bonded by fixing glue.

Example four:

in a preferred embodiment, as shown in fig. 6, the plurality of display units 120 have different thicknesses, and the plurality of display units 120 having different thicknesses are aligned on one side in the thickness direction and arranged in order of thickness.

In the above-described embodiment, as a preferred embodiment, one side of the display unit 120 having the smallest thickness is attached to one side of the first lens 10, and the other side of the display unit 120 having the smallest thickness is abutted to the other display unit 120; one side of the display unit 120 having the thickest thickness is attached to one side of the second lens 11, and the other side of the display unit 120 having the thickest thickness abuts against the other display unit 120.

In this embodiment, the defined length, width and thickness can be understood as the length, width and height of a conventional cube, and a manner of splicing three display units 120 is described, wherein three display units 120 with the same width, the same length and different thicknesses are selected, in the cross-sectional view of fig. 6, the image display 12 spliced by the three display units 120 is flush with the external direction pointing to the triangle-like space, and the thickness of the display unit 120 close to the first lens 10 is smaller than that of the display unit 120 close to the triangle-like space. The three display units 120 respectively surround the first lens 10 and the second lens 11 to form a triangle-like space. In the cross-sectional view of fig. 6, three display units 120 are bonded together side by side, and in the schematic structural view, three display units 120 are bonded side by side.

The fixing modes of the three display units 120 are divided into two types, the first mode is that every two adjacent display units 120 can be fixed by a fixing frame with a preset shape, for example, the fixing frame with the same length and the same width as the display units 120 and the thickness increasing from left to right is selected to respectively fix the three display units 120, and the fixing mode can be selected from the existing technologies for fixing, which is not described herein again. The second way is that every two adjacent display units 120 are bonded by fixing glue, for example, the contact surface between every two adjacent display units 120 is bonded by fixing glue.

It should be noted that, the seam processing between every two adjacent display units 120 and the difference problem caused by the bonding of the fixing glue can be overcome or improved in a manner of improving the process, which does not affect the technical scheme and the achieved technical effect of the present application, that is, the difference caused by the process can be ignored, and is not described herein again.

EXAMPLE five

In a preferred embodiment, the first lens element 10 and the second lens element 11 are both thick free-form lenses, so that the image generated by the image display 12 is reflected and imaged in the first lens element 10 and the second lens element 11.

In this embodiment, the first lens element 10 and the second lens element 11 are two lens elements (lenses), respectively, which are used as optical lenses and are combined through the bottom to form a lens combination. In addition, on the first plane (i.e., the plane formed by the Y axis and the Z axis), the appearance of the lens combination formed by the first lens 10 and the second lens 11, and the lens combination 1a (the first lens 10 and the second lens 11) at the opening end of the top part are recombined with the image display 12/the spliced image display 120, respectively, to form the near-eye see-through head display optical system of the present invention.

In the above-mentioned technical solution, as a preferred embodiment, the first lens 10 has a first surface 100 and a second surface 101, and the second lens 11 has a third surface 110 and a fourth surface 111.

In this embodiment, the four surfaces are free-form surfaces, and on the first plane, the projection line segments of the first surface 100 and the second surface 101 are parallel to each other, and the projection line segments of the third surface 110 and the fourth surface 111 are also parallel to each other, which prevents the light from generating aberration when encountering the lens. The first lens 10 and the second lens 11 may be made of optical Glass (optical Glass) or Polymer (Polymer).

In this embodiment, the first lens 10 and the second lens 11 may be made of a polymer engineering plastic, for example: methyl methacrylate (i.e., acryl, PMMA), or one of Polycarbonate (PC), or polypropylene (PP), or polyethylene terephthalate (PET), or Nylon (Nylon).

In this embodiment, in order to avoid distortion or spherical aberration of the first lens element 10 and the second lens element 11 during imaging, in a preferred embodiment, the curved surface thicknesses of the first lens element 10 and the second lens element 11 are uniform (uniform). For example, the thickness of the curved surfaces of the first lens 10 and the second lens 11 is 1 to 3mm, preferably 2.5 mm.

In the above technical solution, as shown in fig. 2 or fig. 3, as a preferred embodiment, the first surface 100, the second surface 101, the third surface 110, and the fourth surface 111 satisfy the following equation (1):

is a normalized angular coordinate.

In this embodiment, the z-direction power is controlled by two curved reflective surfaces formed by Zernike Polynomials (Zernike Polynomials), and the distortion and curvature of field of the image are eliminated by two off-axis second and

third surfaces

101 and 110 compensating each other. The parameters are subjected to various optical path conditions to determine the actual value of each parameter. In practice, the actual values under various conditions in the formula (1) are determined by the optical simulation software to form the exact shapes of the first surface 100 to the fourth surface 111, thereby completing the casting of the first lens 10 and the second lens 11.

EXAMPLE six

Next, on the basis of the embodiment of the display unit splicing scheme, please refer to fig. 8, which is a light path diagram of a second embodiment of the near-eye see-through head display optical system 1 according to the present invention, and for convenience of illustration, the light path diagram is illustrated by using only a side view of the first lens 10 in the near-eye see-through optical system; in fact, when the first lens element 10 and the second lens element 11 are viewed from the + X axis toward the origin of coordinates, the first lens element 10 and the second lens element 11 are superposed because of the symmetry relationship between the two lens elements. In fig. 8, which is a diagram of the light paths of the first light L1 and the second light L2, which is a simplified diagram of the light rays, the maximum field-of-view edge light (the first light L1) and the minimum field-of-view edge light (the second light L2) of the surface light source of the image display 12 represent the optical behavior of the surface light source on the first plane with respect to the first lens 10 and the second lens 12. And all light rays in the image emitted by the image display 12/120 must have a path in the first plane between the first light ray L1 and the second light ray L2. In this embodiment, the actual optical path of the near-eye see-through head-display optical system 1 is that the image display 12/120 emits the first light L1 and the second light L2, and then enters the optical combination of the first lens 10 and the second lens 11, and the first reflection occurs on the third surface 110, and after the first reflection occurs on the second surface 101, the first light L1 and the second light L2 can enter the eye E of the user after passing through the third surface 110 of the second lens 11 and transmitting the fourth surface 111 again. At this time, the second surface 101 and the third surface 110 are semi-reflecting and semi-transmitting surfaces. In order to achieve the above-mentioned optical path, in the optical simulation, in addition to the requirement of first conforming to the formula (1), the first light L1, the second light L2, the second surface 101 and the third surface 110 should satisfy the formulas (2) to (4) to confirm the shapes of the last second surface 101 and the third surface 110.

In the above technical solution, as a preferred embodiment, the second surface 101, the third surface 110, and the fourth surface 111 should satisfy conditional equations (2) to (4):

wherein, the algebra Y, Z in the formulas (2) to (4) respectively represents the coordinate value of a certain point under the card coordinate system of the present invention, and each subscript represents each different point, as shown in fig. 8, L1 is the first light ray, and L2 is the second light ray. Wherein b is an emission point of the first light L1 emitted by the image display 12, b2 is an intersection point of the first light L1 reflected and the third surface 110, and b1 is an intersection point of the first light L1 reflected and the second surface 101 reflected; b3 is the intersection point of the first light ray L1 when refracted with the third surface 110, a is the emission point of the second light ray L2 emitted by the image display 12/120, a2 is the intersection point of the second light ray L2 when reflected with the third surface 110, and a1 is the intersection point of the second light ray L2 when reflected with the second surface 101; a3 is the intersection point of the second light ray L2 with the third surface 110 when refracted.

It should be noted that the boundary conditions a and b at the starting point of the near-eye see-through head-view display optical system 1 shown in fig. 8 are calculated directly from the light source (image display 12/120), while the boundary conditions at the starting point of the background art are calculated by the optical system (prism). When the boundary condition of the starting point is calculated by the optical system (prism), the calculated optical path and the actual optical path have a displacement phenomenon. When the boundary condition of the starting point is calculated by the light source, the calculated light path is closer to the actual light path, so that the probability of dispersion and distortion of imaging can be reduced. In addition, the first lens element 10 and the second lens element 11 of the near-eye see-through head-display optical system 1 shown in fig. 8 are transparent, so that the user's eyes can see through the outside directly.

EXAMPLE seven

Finally, referring to fig. 9, a light path diagram of another embodiment of the present invention is shown on the basis of the above embodiment of the display unit splicing scheme. In which fig. 9 is formed by simplifying the optical path of fig. 9 and marking the angle for clarity of the position of the angle.

All the emitted light of the image display 12 is totally reflected on the second surface 101 only when the incident angles to the second surface 101, such as θ mi1 and θ mi2 in fig. 9, are larger than the critical angle (i.e. formula (5)).

Where n' represents the refractive index of the first lens 10 or the second lens 11.

The first lens 10 and the second lens 11 are made of transparent optical materials with refractive indexes larger than 1, so that on one hand, batch processing can be performed in an injection molding mode, and on the other hand, the weight of the helmet-mounted display can be effectively reduced. In one embodiment of the present invention, if the refractive index n of the material used is 1.492, the incident angle of all the image light emitted from the image display 12 at the first reflection on the second surface 101 must be 42.2 °, otherwise the light will partially penetrate the second surface 101, resulting in a blurred image seen by the user. The light beams of the first light beam L1 and the second light beam L2 passing through the second surface 101 are light beams that the user's eyes do not want to see, because they can generate partial reflected light on the first surface 100 and can enter the user's eyes E after being combined with other ambient light beams, which causes stray light, interferes with the first light beam L1 and the second light beam L2, and causes the brightness of the image seen by the user's eyes E to be reduced and the image to be blurred. In an embodiment of the present invention, in order to control all image light rays to be totally reflected on the second surface 101, the incident angle of the first light ray L1 on the second surface 101 must be controlled to be greater than 42.2 °, so that all image light rays emitted from the image display 12 can be controlled to be totally reflected on the second surface 101.

It should be noted that the present invention is a specific embodiment of how to increase the longitudinal viewing angle on the basis of the existing large field angle (FOV: 100.8 °), specifically how to change the longitudinal viewing angle by improving the image display 12, and how to increase the total viewing angle. For prior art, reference is made to publication No. CN109782441A, which is entitled near-eye perspective head-display optical system and is not described herein again.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims

1. A near-eye perspective head display optical system comprises a first lens, a second lens and an image display; one side of the first lens is attached to one side of the image display, one side of the second lens is attached to the other side of the image display, the other side of the first lens is attached to the other side of the second lens, and the first lens, the second lens and the image display are distributed to form a triangle-like space; the image display is characterized by being formed by splicing at least two display units.

2. The optical system of claim 1, wherein the display units are stacked in a step-like parallel offset arrangement.

3. The near-eye perspective head-display optical system according to claim 2, wherein the plurality of display units have the same length, width and thickness, and are fixedly disposed at the step teeth of the step-shaped baffle, or the side edges of the plurality of display units are fixedly connected by a fixed connection structure to form step-shaped arrangement and splicing.

4. The system of claim 2, wherein the plurality of display units are different in length, and the plurality of display units having different lengths are aligned on one side in the length direction and arranged in a length-size order.

5. The system of claim 4, wherein the plurality of display units have an unshielded portion as a display area.

6. The system of claim 4, wherein a plurality of the display units are attached to one side of the second lens at the side aligned in the longitudinal direction; one side of the display unit with the longest length is attached to one side of the first lens.

7. The system of claim 2, wherein the plurality of display units have different thicknesses, and the plurality of display units having different thicknesses are aligned on one side in the thickness direction and arranged in order of thickness.

8. The system of claim 7, wherein one side of the thinnest display unit is attached to one side of the first lens, and the other side of the thinnest display unit is abutted to the other display units; one side of the display unit with the thickest thickness is attached to one side of the second lens, and the other side of the display unit with the thickest thickness is abutted to the other display units.

9. The near-eye perspective head display optical system according to any one of claims 4 to 8, wherein every two adjacent display units are fixed by a fixing frame having a predetermined shape, or every two adjacent display units are bonded by a fixing glue.

10. The system of claim 9, wherein the display unit is a bezel-less tiled screen.

11. The system of claim 1, wherein the first lens and the second lens are both uniform-thickness free-form surface lenses for forming an image of the image display by reflection in the first lens and the second lens.

12. The system of claim 11, wherein the first lens has a first surface and a second surface, and the second lens has a third surface and a fourth surface.

13. The near-eye perspective head-displaying optical system of claim 12, wherein the first surface, the second surface, the third surface, and the fourth surface satisfy the following equation (1):

is a normalized angular coordinate.

14. The near-eye perspective head-viewing optical system of claim 12, wherein the second surface, the third surface, and the fourth surface should satisfy conditional equations (2) to (4):

15. The near-eye perspective head-viewing optical system of claim 12, wherein the second surface and the third surface should satisfy conditional equation (5),

wherein n' represents a refractive index of the first lens or the second lens.

16. The system of claim 1, wherein the first lens and the second lens are integrally formed.