CN107918205B

CN107918205B - Optical lens system for head-mounted display device capable of improving user experience

Info

Publication number: CN107918205B
Application number: CN201711302146.1A
Authority: CN
Inventors: 不公告发明人
Original assignee: Jiangxi Changyi Photoelectric Co ltd
Current assignee: JIANGXI CHANGYI PHOTOELECTRIC Co.,Ltd.
Priority date: 2016-04-29
Filing date: 2016-04-29
Publication date: 2021-03-09
Anticipated expiration: 2036-04-29
Also published as: CN107817608A; CN107817607A; CN107817608B; CN107807449A; CN105739084A; CN107918205A; CN105739084B

Abstract

The invention relates to an optical lens system for a head-mounted display device, which can improve user experience. The invention discloses an optical lens system, which sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens along an optical axis from a light-emitting side to a light-entering side, wherein each lens has a refractive index, the first lens is a positive focal power lens, the second lens is a positive focal power lens, the third lens is a positive focal power lens, the fourth lens is a negative focal power lens, the fifth lens is a positive focal power lens, and the sixth lens is a negative focal power lens. The invention also discloses a head-mounted display device with the optical lens system. The invention has the advantages of light weight, compact structure, larger field angle, exit pupil diameter and exit pupil distance, improved user experience, excellent imaging quality, high resolution and low cost.

Description

Optical lens system for head-mounted display device capable of improving user experience

Technical Field

The present invention relates to an optical lens system for a head-mounted display device, which can improve user experience, and in particular, to a head-mounted display device using six-piece lenses and an optical lens system thereof.

Background

In recent years, due to the rise of wearable electronic devices, miniaturized display modules including optical lens systems and micro displays have been developed, and are widely used in head-mounted display devices. The head-mounted display equipment is widely applied to the fields of military affairs, aerospace, medical treatment, entertainment, simulation training and the like. As head-mounted display devices are more widely used, requirements on imaging quality and use comfort (the larger the field angle, the exit pupil diameter and the exit pupil distance, the smaller the volume, the lighter the weight, and the higher the use comfort) of the head-mounted display devices are higher, and the quality of the imaging quality and the use comfort are mainly determined by the design of the optical eyepiece system.

The patent publication: CN104570323A proposes a head-mounted eyepiece system and a head-mounted display device, which are eyepiece systems using 4-piece lenses, and although the size is small and the weight is light, the distortion is large and the exit pupil is small, which cannot meet the increasing demands of consumers; research on an optical design method of a 3D virtual helmet-mounted display based on ZEMAX, infrared and laser engineering, 2008,37:279-282 and provides an optical system for helmet-mounted display, which is formed by combining six lenses, has good imaging quality, but has a long total length, an insufficient exit pupil diameter and a short effective exit pupil distance; the patent publication: the eyepiece proposed by CN101609208A is also formed by combining six lenses, and although the eyepiece has better imaging quality, the diameter of the exit pupil is smaller, the distance of the exit pupil is shorter, the use comfort of a user is reduced, the processing difficulty is high, and the substrate is thicker.

In addition, in the eyepiece lens system, when the size of an object is determined, the smaller the focal length, the larger the angle of view, and the larger the magnification of the system, and the difficulty of design increases. Although the number of the head-wearing systems in the market is small, the field angle, the exit pupil diameter and the exit pupil distance of most products are small, and the use comfort of users is reduced.

Disclosure of Invention

The present invention is directed to solving the above-mentioned problems and providing an optical lens system and a head-mounted display device with light weight, compact structure, large field angle, large exit pupil diameter and large exit pupil distance, improved user experience, excellent imaging quality, high resolution and low cost.

To achieve the above object, the present invention discloses an optical lens system, which comprises, in order along an optical axis, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element from a light-emitting side to a light-entering side, wherein each lens element has a refractive index, and has a first surface facing the light-emitting side and allowing light to pass therethrough and a second surface facing the light-entering side and allowing light to pass therethrough, wherein:

the first lens is a positive focal power lens, and the first surface of the first lens is a convex surface part;

the second lens is a positive focal power lens, and the first surface of the second lens is a convex surface part;

the third lens is a positive focal power lens, the first surface of the third lens is a convex surface part, and the second surface of the third lens is a convex surface part;

the fourth lens is a negative focal power lens, the first surface of the fourth lens is a concave surface part, and the second surface of the fourth lens is a concave surface part;

the fifth lens is a positive focal power lens, and the first surface of the fifth lens is a convex surface part;

the sixth lens is a negative focal power lens;

the third lens and the fourth lens form a combined lens;

wherein the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the combined lens element is f34, the focal length of the fifth lens element is f5, the focal length of the sixth lens element is f6, the system focal length of the optical lens system is fs, and the following relationships are satisfied:

2.3<f1/fs<5.5

1.8<f2/fs<2.8

-4<f34/fs<-1.4

0.5<f5/fs<1.2

-2<f6/fs<-0.8。

further, the radius of curvature of the second surface of the third lens is the same as the radius of curvature of the first surface of the fourth lens.

Furthermore, the second surface of the third lens and the first surface of the fourth lens are glued with each other.

Furthermore, the fifth lens and the sixth lens are made of optical plastic.

Further, the first surface and the second surface of the fifth lens and the sixth lens are aspheric surfaces.

Further, the exit pupil distance of the optical lens system is lep, and satisfies the relation: lep/fs is more than or equal to 0.9 and less than or equal to 1.3.

Further, the sum of air gaps on the optical axis between the first lens and the sixth lens is AGa, and the following conditional expressions are also satisfied: 7 is less than or equal to lep/AGa is less than or equal to 19.

The present invention also provides a head-mounted display device, comprising:

a housing; and

a display module mounted in the housing, comprising:

at least one optical lens system as described above,

and the display screen is positioned on the optical axis of the second surface of the sixth lens facing the light incidence side.

Further, the distance between the observation point of the optical lens system for human eye observation and the first surface of the first lens on the optical axis is greater than or equal to 21 mm.

The invention has the beneficial technical effects that:

according to the head-mounted display device and the optical lens system thereof, the concave-convex curved surface arrangement of each lens is controlled, other optical relational expressions are used for controlling relevant parameters, and the glass and plastic lenses are matched for use, so that the head-mounted display device has the characteristics of light weight, compact structure, larger viewing angle, larger exit pupil diameter and larger exit pupil distance, improved user experience, excellent imaging quality, high resolution and low cost.

Drawings

FIG. 1 is a schematic cross-sectional view of a first embodiment of the present invention;

FIG. 2 is a diagram showing the variation of field curvature with the normalized field of view of the optical lens system of the first embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 3 is a schematic diagram of distortion of the optical lens system of the first embodiment as a function of normalized field of view;

FIG. 4 is a diagram showing vertical axis chromatic aberration of the optical lens system of the first embodiment as a function of normalized field of view;

FIG. 5 is a schematic cross-sectional view of a second embodiment of the present invention;

FIG. 6 is a diagram showing the variation of field curvature with the normalized field of view of the optical lens system of the second embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 7 is a schematic diagram of distortion of the optical lens system of the second embodiment as a function of normalized field of view;

FIG. 8 is a diagram showing vertical axis chromatic aberration of the optical lens system of the second embodiment as a function of normalized field of view;

FIG. 9 is a schematic cross-sectional view of a third embodiment of the present invention;

FIG. 10 is a graph showing the variation of field curvature with respect to the normalized field of view of the optical lens system of the third embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 11 is a schematic diagram of distortion of the optical lens system of the third embodiment as a function of normalized field of view;

FIG. 12 is a diagram showing vertical axis chromatic aberration of the optical lens system of the third embodiment as a function of normalized field of view;

FIG. 13 is a schematic cross-sectional view of a fourth embodiment of the present invention;

FIG. 14 is a graph showing the variation of field curvature with respect to the normalized field of view of the optical lens system of the fourth embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 15 is a schematic diagram of distortion of the optical lens system of the fourth embodiment as a function of normalized field of view;

FIG. 16 is a diagram showing vertical axis chromatic aberration of the optical lens system of the fourth embodiment as a function of normalized field of view;

FIG. 17 is a schematic cross-sectional view of a fifth embodiment of the present invention;

FIG. 18 is a graph showing the variation of field curvature with respect to the normalized field of view of the optical lens system of the fifth embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 19 is a schematic diagram of distortion of the optical lens system of the fifth embodiment as a function of normalized field of view;

fig. 20 is a schematic diagram showing a change in vertical axis chromatic aberration with a normalized field of view of the optical lens system of the fifth embodiment;

FIG. 21 is a schematic cross-sectional view of a sixth embodiment of the present invention;

FIG. 22 is a graph showing the variation of field curvature with respect to the normalized field of view of the optical lens system of the sixth embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 23 is a schematic diagram of distortion of the optical lens system of the sixth embodiment as a function of normalized field of view;

fig. 24 is a schematic diagram showing a change in vertical axis chromatic aberration with a normalized field of view of the optical lens system of the sixth embodiment;

FIG. 25 is a schematic cross-sectional view of a seventh embodiment of the present invention;

FIG. 26 is a graph showing the variation of field curvature with respect to the normalized field of view of the optical lens system of the seventh embodiment (illustrating that xt 'is meridian field curvature and xs' is sagittal field curvature);

FIG. 27 is a schematic diagram of distortion of the optical lens system of the seventh embodiment as a function of normalized field of view;

fig. 28 is a schematic diagram showing a change in vertical axis chromatic aberration with a normalized field of view of the optical lens system of the seventh embodiment.

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

In the present specification, the term "a lens has a positive refractive power (or a negative refractive power)" means that the refractive index of the lens on the optical axis calculated by the gaussian optical theory is positive (or negative). The method for determining the concave and convex surfaces of the lens is as follows: the concave and convex shapes of the surface shape of the lens are determined at the light exit side a1 or the light entrance side a2 at the intersection point of the light beam (or the light beam extension line) passing through the region in parallel with the optical axis (light beam focus determination method). For example, when the light passes through the region, the light is focused toward the light-emitting side a1, and the focal point of the optical axis I is located at the light-emitting side a1, the region is a convex surface. Conversely, if the light beam passes through the region, the light beam diverges such that the extension line of the light beam and the focal point of the optical axis I are on the light incident side a2, and the region is a concave portion. In addition, the determination of the surface shape of the lens may be performed by determining whether or not the surface shape of the lens is concave or convex based on the positive or negative R value (which refers to the radius of curvature of the optical axis and is generally referred to as the R value in a lens database (lens data) in optical software) according to a determination method of a person of ordinary skill in the art. With respect to the first surface toward the light exit side a1, when the R value is positive, it is determined as a convex surface portion, and when the R value is negative, it is determined as a concave surface portion; on the other hand, with respect to the second surface facing the light entrance side a2, when the R value is positive, it is determined as a concave surface portion, and when the R value is negative, it is determined as a convex surface portion, and the method determines the concavity and convexity in the same manner as the light focus determination.

To facilitate the presentation of the parameters to which the invention refers, it is defined in the description and in the attached drawings:

a radius of curvature of the first surface S of the first lens L is R, a radius of curvature of the second surface S of the first lens L is R, a thickness of the first surface S to the second surface S of the first lens L on the optical axis is D, a radius of curvature of the first surface S of the second lens L is R, a radius of curvature of the second surface S of the second lens L is R, a thickness of the first surface S to the second surface S of the second lens L on the optical axis is D, a radius of curvature of the first surface S of the third lens L is R, a radius of curvature of the second surface S of the third lens L is R, a thickness of the first surface S to the second surface S of the third lens L on the optical axis is D, a radius of curvature of the first surface S of the fourth lens L is R, a radius of curvature of the second surface S of the fourth lens L is R, a thickness of the first surface S to the second surface S of the fourth lens L on the optical axis is D, the radius of curvature of the first surface S51 of the fifth lens L5 is R9, the radius of curvature of the second surface S52 of the fifth lens L5 is R10, the thickness of the first surface S51 to the second surface S52 of the fifth lens L5 on the optical axis is D5, the radius of curvature of the first surface S61 of the sixth lens L6 is R11, the radius of curvature of the second surface S62 of the sixth lens L6 is R12, and the thickness of the first surface S61 to the second surface S62 of the sixth lens L6 on the optical axis is D6; the distance between the second surface S12 of the first lens L1 and the first surface S21 of the second lens L2 on the optical axis I, that is, the air gap between the first lens L1 and the second lens L2 is d 12; the distance between the second surface S22 of the second lens L2 and the first surface S31 of the third lens L3 on the optical axis I, that is, the air gap between the second lens L2 and the third lens L3 is d 23; the distance between the second surface S32 of the third lens L3 and the first surface S41 of the fourth lens L4 on the optical axis I, that is, the air gap between the third lens L3 and the fourth lens L4 is d 34; the distance between the second surface S42 of the fourth lens L4 and the first surface S51 of the fifth lens L5 on the optical axis I, that is, the air gap between the fourth lens L4 and the fifth lens L5 is d 45; the distance between the second surface S52 of the fifth lens L5 and the first surface S61 of the sixth lens L6 on the optical axis I, that is, the air gap between the fifth lens L5 and the sixth lens L6 is d 56; the focal length of the first lens L1 is f 1; the focal length of the second lens L2 is f 2; the focal length of the combined lens L34 formed by the third lens L3 and the fourth lens L4 is f 34; the focal length of the fifth lens L5 is f 5; the focal length of the sixth lens L6 is f 6; the system focal length of the optical lens system is fs; the sum of all air gaps on the optical axis I between the first lens L1 and the sixth lens L6 is AGa, and the exit pupil distance (distance of exit pupil, the distance from the intersection of the first surface S11 of the first lens L1 of the optical lens system and the optical axis to the intersection of the exit pupil plane and the optical axis) of the optical lens system is lep.

The head-mounted display device of the present invention includes: a housing; and a display module installed in the casing, the display module including: the display screen is positioned on an optical axis of the second surface of the sixth lens facing the light incidence side.

The optical lens system of the invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in sequence along an optical axis from a light-emitting side to a light-entering side, wherein each lens has a refractive index and is provided with a first surface facing the light-emitting side and allowing light to pass and a second surface facing the light-entering side and allowing light to pass, wherein:

the sixth lens is a negative focal power lens;

the third lens and the fourth lens form a combined lens;

2.3<f1/fs<5.5

1.8<f2/fs<2.8

-4<f34/fs<-1.4

0.5<f5/fs<1.2

-2<f6/fs<-0.8。

preferably, the radius of curvature of the second surface of the third lens is the same as the radius of curvature of the first surface of the fourth lens in order to achieve a better optical effect and a shorter system length. And the second surface of the third lens and the first surface of the fourth lens are cemented with each other.

Furthermore, in order to make the lens system thinner, lighter, lower in cost and better in optical performance, the fifth lens element and the sixth lens element are both made of optical plastic material, and are both aspheric lens elements, and the aspheric expression thereof is

Wherein Y is the distance between a point on the aspheric curve and the optical axis I; z is the depth of the aspheric surface (the vertical distance between the point on the aspheric surface which is Y away from the optical axis I and the tangent plane tangent to the vertex on the optical axis I of the aspheric surface); r is the radius of curvature of the lens surface; k is cone constant; a2i is the 2 i-th order aspheric coefficient.

The optical lens system may further include an aperture stop (aperture stop) disposed on an exit pupil (exit pupil) surface of the optical lens system, and a protective glass disposed on an optical axis between the sixth lens and the display screen.

Further, in order to make the optical lens system thinner and lighter, and have larger field angle, exit pupil diameter and exit pupil distance, and also have better optical performance, the exit pupil distance, focal length of the lens and the air gap configuration between the lenses are important, and some limitations are proposed herein:

0.9≤lep/fs≤1.3，

7≤lep/AGa≤19。

the optical lens system of the invention only has the six lenses with the refractive indexes, and the detailed characteristics of each lens are designed, so that the optical lens system has good optical performance, ensures excellent imaging quality, and has the characteristics of light weight, compact structure, larger angle of view, larger exit pupil diameter and exit pupil distance, improved user experience and low cost.

The invention will now be further described with reference to the accompanying drawings and detailed description.

The first embodiment is as follows:

as shown in fig. 1, the optical lens system of the present embodiment sequentially includes, along an optical axis I, from an exit side a1 to an entrance side a 2: a diaphragm 2, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5 and a sixth lens element L6, each of which has refractive index and has a first surface facing the light-emitting side a1 and allowing light to pass therethrough and a second surface facing the light-entering side a2 and allowing light to pass therethrough.

The stop (aperture stop)2 is an equivalent stop, and may not be a physical stop in practical applications, and the stop 2 is disposed on the optical axis I of the first lens L1 facing the light-emitting side a1 and located at the exit pupil (exit pupil) surface of the optical lens system. The protective glass 3 is disposed on the optical axis I of the sixth lens L6 facing the light incident side a2, is close to the display screen 1, and is usually made of flat optical material, and does not affect the focal length of the optical lens system of the present invention.

In this embodiment, the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 are all spherical lenses and are made of glass, but in other embodiments, other materials such as plastic may be used; the fifth lens L5 and the sixth lens L6 are made of optical plastic, so that the system has light weight and low cost, and in other embodiments, other materials such as glass can be used.

The first lens L1 is a positive power lens, and the first surface of the first lens L1 is a convex surface portion at S11 and the second surface of the first lens L12 is a convex surface portion.

The second lens L2 is a positive power lens, and the first surface S21 of the second lens L2 is a convex surface portion, and the second surface S22 thereof is a concave surface portion.

The third lens L3 is a positive power lens, and the first surface S31 of the third lens L3 is a convex surface portion, and the second surface S32 thereof is a convex surface portion.

The fourth lens L4 is a negative power lens, and the first surface S41 of the fourth lens L4 is a concave surface portion, and the second surface S42 thereof is a concave surface portion.

The fifth lens L5 is a positive power lens, the first surface S51 of the fifth lens L5 is a convex surface portion, the second surface S52 is a convex surface portion, and the first surface S51 and the second surface S52 are both aspheric surfaces, and the aspheric coefficients thereof are as shown in table two.

The sixth lens L6 is a negative power lens, the first surface S61 of the sixth lens L6 is a concave surface portion, the second surface S62 is a concave surface portion, and the first surface S61 and the second surface S62 are both aspheric surfaces, and aspheric coefficients thereof are as shown in table two.

The third lens L3 and the fourth lens L4 constitute a combined lens L34.

Here, the radius of curvature R6 of the second surface S32 of the third lens L3 of this embodiment is the same as the radius of curvature R7 of the first surface S41 of the fourth lens L4. The third lens L3 and the fourth lens L4 are integrally bonded to each other.

In this embodiment, the optical parameters of the respective lenses from the first lens L1 to the sixth lens L6 are as shown in table one

TABLE I, optical parameter data of each lens of the first embodiment

TABLE II aspherical parameters of the first example

In this embodiment, the air gap d between the first lens L and the second lens L is 0.100mm, the air gap d between the second lens L and the third lens L is 0.100mm, the air gap d between the third lens L and the fourth lens L is 0mm, the air gap d between the fourth lens L and the fifth lens L is 2.080mm, and the air gap d between the fifth lens L and the sixth lens L is 0.120mm, so that the total sum AGa of all the air gaps on the optical axis I between the first lens L to the sixth lens L is calculated to be d + d + d + d 2.4mm, the focal length f of the first lens L is mm, the focal length f of the second lens L is 44.000mm, the focal length f of the combination lens L is-mm, the focal length f of the fifth lens L is mm, the focal length f of the sixth lens L is-mm, the focal length fs of the optical lens system is mm, the exit pupil distance Lep of the optical lens system is 24.000 mm.

Through simple calculation, the following results are obtained: 2.674 for f1/fs, 2.125 for f2/fs, 1.891 for f34/fs, 0.837 for f5/fs, 1.646 for f6/fs, 10.000 for Lep/AGa, and 1.158 for Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

According to the optical lens system described above, the head mounted display device of this embodiment includes: a casing and install a display module in this casing, this display module includes: the display screen 1 is disposed on the light incident side a2 of the optical lens system and is located on the optical axis I of the light incident side a2 of the cover glass 3. In this embodiment, the display screen 1 is a 0.7 inch micro display screen.

In this embodiment, the field angle reaches 48 °, the observation is facilitated, the exit pupil diameter reaches 9.000mm, the pupil distance can be easily adjusted, the exit pupil distance (i.e., the distance between the observation point of the optical lens system for observation by the human eye and the first surface S11 of the first lens L1 on the optical axis I) reaches 24.000mm, and a near-far observer can wear glasses to watch, thereby improving the user experience. Meanwhile, as can be seen from fig. 2 to 4, the optical lens system corrects aberrations such as field curvature, astigmatism and chromatic aberration of magnification, has good imaging quality, has a distortion of less than 2.5%, and shows that the optical lens system has high optical performance and can provide good imaging quality within an acceptable range of human eyes.

Example two:

as shown in fig. 5, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the second surface S22 of the second lens L2 and the second surface S62 of the sixth lens L6 of this embodiment are convex surfaces, and the optical parameters and aspheric coefficients of the lenses of this embodiment are slightly different from those of the first embodiment, and are shown in table three and table four, respectively

TABLE III optical parameter data of each lens of the second embodiment

TABLE IV aspheric parameters of the second embodiment

In this embodiment, the air gap d12 between the first lens L1 and the second lens L2 is 0.100mm, the air gap d23 between the second lens L2 and the third lens L3 is 0.100mm, the air gap d34 between the third lens L3 and the fourth lens L4 is 0mm, the air gap d45 between the fourth lens L4 and the fifth lens L5 is 1.890mm, the air gap d56 between the fifth lens L5 and the sixth lens L6 is 0.120mm, so that the sum AGa of all air gaps between the first lens L1 and the sixth lens L6 on the optical axis I is calculated to be d12+ d23+ d34+ d45+ 45mm 2.21mm, the focal length f 45 of the first lens L45 is 45mm, the focal length f of the second lens L45 mm is 45mm, the focal length 45 of the combined optical system is 45mm, the focal length 45mm of the focal length 45L 45 mm-45 mm, the focal length 45mm is 45mm of the focal length 45mm, the exit pupil distance Lep of the optical lens system was 23.000 mm.

Through simple calculation, the following results are obtained: 2.673 for f1/fs, 2.291 for f2/fs, 2.271 for f34/fs, 0.856 for f5/fs, 361.772 for f6/fs, 10.400 for Lep/AGa and 1.173 for Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

In the embodiment, the field angle reaches 50 degrees, observation is facilitated, the exit pupil diameter reaches 8.500mm, the pupil distance can be easily adjusted, the exit pupil distance reaches 23.000mm, a near-far viewer can wear glasses to watch, user experience is improved, meanwhile, the fifth lens L5 and the sixth lens L6 are aspheric plastic lenses, the optical lens system is lighter and thinner, and cost is lower. Suitable for 0.7 inch micro display screen.

Meanwhile, as can be seen from fig. 6 to 8, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

Example three:

as shown in fig. 9, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the second surface S22 of the second lens L2 of this embodiment is convex, and the second surface S62 of the sixth lens L6 is convex, and the optical parameters and aspheric coefficients of the lenses of this embodiment are slightly different from those of the first embodiment, and the optical parameters and aspheric coefficients of the lenses of this embodiment are as shown in table five and table six, respectively

TABLE V, optical parameter data of each lens of the third embodiment

Table six, aspheric parameters of the third embodiment

Noodle

K

a2

a4

a6

a8

a10

S51

-20.1

3.10E-04

2.40E-06

-3.30E-08

S52

0.5

7.20E 04

1.80E 06

3.20E 08

S61

1.3

3.60E-04

4.50E-06

-1.40E-08

-6.50E-12

S62

192.8

-5.10E-04

2.00E-05

-1.40E-07

In this embodiment, the air gap d12 between the first lens L1 and the second lens L2 is 0.100mm, the air gap d23 between the second lens L2 and the third lens L3 is 0.100mm, the air gap d34 between the third lens L3 and the fourth lens L4 is 0mm, the air gap d45 between the fourth lens L4 and the fifth lens L5 is 1.614mm, the air gap d56 between the fifth lens L5 and the sixth lens L6 is 0.120mm, so that the sum AGa of all air gaps on the optical axis I between the first lens L1 and the sixth lens L6 is calculated to be d12+ d23+ d34+ d45+ d56 mm, the focal length f 56 mm of the first lens L56 is 56 mm, the focal length f of the second lens L56 mm is 56 mm, the focal length f of the combined lens system is 56 mm, the focal length 56 mm of the lens system 56 mm is 56 mm, the focal length 56 mm of the focal length 56 mm of the lens system 56 mm, the exit pupil distance Lep of the optical lens system was 21.000 mm.

Through simple calculation, the following results are obtained: 3.090 is f1/fs, 2.258 is f2/fs, 2.378 is f34/fs, 0.751 is f5/fs, 10.858 is f6/fs, 10.858 is Lep/AGa and 1.144 is Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

In this embodiment, the field angle reaches 53 °, and is convenient for observe, and exit pupil diameter reaches 8.500mm, can adjust interpupillary distance easily, and exit pupil distance reaches 21.000mm, and near farsighted can wear glasses and watch, has improved user experience and has felt from, and fifth lens L5 and sixth lens L6 adopt aspheric surface plastic lens, make this optical lens system lighter and thinner, and the cost is lower. Suitable for 0.7 inch micro display screen.

Meanwhile, as can be seen from fig. 10 to 12, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

Example four:

as shown in fig. 13, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the second surface S22 of the second lens L2 of this embodiment is a plane, the second surface S62 of the sixth lens L6 is a convex surface, and the optical parameters and aspheric coefficients of the lenses of this embodiment are slightly different from those of the first embodiment, which are shown in tables seven and eight, respectively

TABLE seventh and fourth examples of optical parameter data for each lens

Aspherical surface parameters of the eighth and fourth embodiments

In this embodiment, the air gap d between the first lens L and the second lens L is 0.100mm, the air gap d between the second lens L and the third lens L is 0.100mm, the air gap d between the third lens L and the fourth lens L is 0mm, the air gap d between the fourth lens L and the fifth lens L is 1.651mm, the air gap d between the fifth lens L and the sixth lens L is 0.120mm, so that the total sum AGa of all the air gaps on the optical axis I between the first lens L to the sixth lens L is calculated to be d + d + d + d 1mm, the focal length f of the first lens L is mm, the focal length f of the second lens L is mm, the focal length f of the combined lens L is-mm, the focal length f of the fifth lens L is mm, the focal length f of the sixth lens L is-mm, the system focal length fs of the optical lens system is mm, the exit pupil distance Lep of the optical lens system was 21.000 mm.

Through simple calculation, the following results are obtained: 3.070 for f1/fs, 2.239 for f2/fs, 2.376 for f34/fs, 0.736 for f5/fs, 1.507 for f6/fs, 10.654 for Lep/AGa and 1.154 for Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

In this embodiment, the field angle reaches 53.5 °, and is convenient for observe, exit pupil diameter reaches 8.500mm, can adjust interpupillary distance easily, and exit pupil distance reaches 21.000mm, and near farsighted can wear glasses and watch, has improved user experience and has felt from, and fifth lens L5 and sixth lens L6 adopt aspheric plastic lens, make this optical lens system lighter and thinner, and the cost is lower. Suitable for 0.7 inch micro display screen.

Meanwhile, as can be seen from fig. 14 to 16, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

Example five:

as shown in fig. 17, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the optical parameters and aspherical surface coefficients of the lenses of this example are slightly different from those of the first example, and the optical parameters and aspherical surface coefficients of the lenses of this example are shown in tables nine and ten, respectively

Optical parameter data of each lens in the ninth and fifth embodiments

Aspherical surface parameters of the tenth and fifth embodiments

Noodle

K

a2

a4

a6

a8

a10

S51

-0.8

2.90E-05

2.50E-06

-3.20E-08

S52

-0.5

3.50E-04

3.40E-06

-3.50E-08

S61

4.4

3.10E-04

3.20E-06

-2.10E-08

-6.50E-12

S62

24.8

-1.60E-04

2.90E-06

-4.50E-08

In this embodiment, the air gap d between the first lens L and the second lens L is 0.080mm, the air gap d between the second lens L and the third lens L is 0.100mm, the air gap d between the third lens L and the fourth lens L is 0mm, the air gap d between the fourth lens L and the fifth lens L is 1.614mm, the air gap d between the fifth lens L and the sixth lens L is 0.100mm, so that the total sum AGa of all the air gaps on the optical axis I between the first lens L to the sixth lens L is calculated to be d + d + d + d 1.894mm, the focal length f of the first lens L is mm, the focal length f of the second lens L is mm, the focal length f of the combination lens L is-mm, the focal length f of the fifth lens L is mm, the focal length f of the sixth lens L is-mm, the system focal length fs of the optical lens system is mm, the exit pupil distance Lep of the optical lens system is 24.000 mm.

Through simple calculation, the following results are obtained: 2.403 for f1/fs, 2.007 for f2/fs, 1.574 for f34/fs, 0.810 for f5/fs, 12.672 for f6/fs, 1.324 for Lep/AGa and 1.158 for Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

In this embodiment, the field angle reaches 48 °, and is convenient for observe, exit pupil diameter reaches 9mm, can adjust interpupillary distance easily, and exit pupil distance reaches 24.000mm, and the near farsighted can wear glasses and watch, has improved user experience and has felt, and fifth lens L5 and sixth lens L6 adopt aspheric plastic lens simultaneously, make this optical lens system lighter and thinner, and the cost is lower. Suitable for 0.7 inch micro display screen.

Meanwhile, as can be seen from fig. 18 to 20, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

Example six:

as shown in fig. 21, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the second surface S22 of the second lens L2 of this embodiment is convex, and the optical parameters and aspheric coefficients of the lenses of this embodiment are slightly different from those of the first embodiment, and are shown in table eleven and table twelve, respectively

TABLE eleventh and sixth examples of optical parameter data for each lens

TABLE twelfth and sixth examples of aspherical surface parameters

In this embodiment, the air gap d between the first lens L and the second lens L is 0.100mm, the air gap d between the second lens L and the third lens L is 0.100mm, the air gap d between the third lens L and the fourth lens L is 0mm, the air gap d between the fourth lens L and the fifth lens L is 1.978mm, the air gap d between the fifth lens L and the sixth lens L is 0.120mm, so that the total sum AGa of all the air gaps on the optical axis I between the first lens L to the sixth lens L is calculated to be d + d + d + d + d + mm, the focal length f of the first lens L is mm, the focal length f of the second lens L is mm, the focal length f of the combination lens L is-mm, the focal length f of the fifth lens L is 15.500mm, the focal length f of the sixth lens L is-27.200 mm, the focal length fs of the optical lens system is mm, the exit pupil distance Lep of the optical lens system was 23.000 mm.

Through simple calculation, the following results are obtained: 2.525 is f1/fs, 2.569 is f2/fs, 2.478 is f34/fs, 0.791 is f5/fs, 10.009 is f6/fs, 10.009 is Lep/AGa and 1.172 is Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

Meanwhile, as can be seen from fig. 22 to 24, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

Example seven:

as shown in fig. 25, each lens structure of the present embodiment is substantially the same as the first embodiment, except that: the second surface S12 of the first lens L1 of this embodiment is concave, and the second surface S22 of the second lens L2 is convex, and the optical parameters and aspheric coefficients of the lenses of this embodiment are slightly different from those of the first embodiment, and the optical parameters and aspheric coefficients of the lenses of this embodiment are as shown in table thirteen and table fourteen, respectively

TABLE thirteen, seventeenth embodiment of the respective lens optical parameter data

TABLE fourteenth, aspherical parameters of the seventh embodiment

In this embodiment, the air gap d12 between the first lens L1 and the second lens L2 is 0.100mm, the air gap d23 between the second lens L2 and the third lens L3 is 0.090mm, the air gap d34 between the third lens L3 and the fourth lens L4 is 0mm, the air gap d45 between the fourth lens L4 and the fifth lens L5 is 2.641mm, the air gap d56 between the fifth lens L5 and the sixth lens L6 is 0.188mm, so that the sum AGa of all air gaps between the first lens L1 to the sixth lens L6 on the optical axis I is calculated to be d12+ d23+ d34+ d45+ d56 is calculated to be 3.019mm, the f1 of the first lens L1 is 1mm, the f of the second lens L1 is a focal length 1mm, the combined focal length 1 f of the fifth lens L1 is 1mm, the focal length 1 is 1mm, the focal length 1mm of the fifth lens L1 f 1mm, the exit pupil distance Lep of the optical lens system is 24.000 mm.

Through simple calculation, the following results are obtained: 5.333 for f1/fs, 1.985 for f2/fs, 3.818 for f34/fs, 0.657 for f5/fs, 0.88 for f6/fs, 7.950 for Lep/AGa, and 1.091 for Lep/fs. The optical lens system of this embodiment satisfies all of the above conditional expressions.

In this embodiment, the field angle reaches 45 °, and is convenient for observe, exit pupil diameter reaches 9mm, can adjust interpupillary distance easily, and exit pupil distance reaches 24.000mm, and the near farsighted can wear glasses and watch, has improved user experience and has felt, and fifth lens L5 and sixth lens L6 adopt aspheric plastic lens simultaneously, make this optical lens system lighter and thinner, and the cost is lower. Suitable for 0.7 inch micro display screen.

Meanwhile, as can be seen from fig. 26 to 28, the optical lens system has better capability of correcting aberrations such as curvature of field, astigmatism, and chromatic aberration of magnification, and thus shows that the optical lens system has higher optical performance and can provide better imaging quality.

In summary, the head-mounted display devices and the optical lens systems thereof according to the embodiments of the present invention control the concave-convex curved surface arrangement of each lens, and control the related parameters by using other optical relational expressions, and use glass and plastic lenses in a matching manner, so that the head-mounted display devices and the optical lens systems thereof have the characteristics of light weight, compact structure, large field angle, large exit pupil diameter and large exit pupil distance, improved user experience, excellent imaging quality, high resolution, and low cost.

While the invention has been particularly shown and 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 as defined by the appended claims.

Claims

1. A head-mounted display device, comprising:

a housing;

a display module installed in the casing;

at least one optical lens system;

at least one display screen;

wherein:

the optical lens system sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from the light-emitting side to the light-in side along an optical axis, wherein each lens has a refractive index and is provided with a first surface facing the light-emitting side and allowing light to pass through and a second surface facing the light-in side and allowing light to pass through;

the display screen is positioned on the optical axis of the second surface of the sixth lens facing the light incidence side;

the distance between an observation point of the optical lens system for human eye observation and the first surface of the first lens on the optical axis is greater than or equal to 21 mm;

the sixth lens is a negative focal power lens;

the third lens and the fourth lens form a combined lens;

the radius of curvature of the second surface of the third lens is the same as the radius of curvature of the first surface of the fourth lens;

the second surface of the third lens and the first surface of the fourth lens are mutually glued;

the optical lens system also comprises a diaphragm and a piece of protective glass, wherein the diaphragm is arranged at the position of the exit pupil surface of the optical lens system, and the protective glass is arranged on the optical axis between the sixth lens and the display screen; wherein the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the combined lens element is f34, the focal length of the fifth lens element is f5, the focal length of the sixth lens element is f6, the system focal length of the optical lens system is fs, and the following relationships are satisfied:

an air gap between the first lens and the second lens is 0.100mm, an air gap between the second lens and the third lens is 0.100mm, an air gap between the third lens and the fourth lens is 0mm, an air gap between the fourth lens and the fifth lens is 2.080mm, and an air gap between the fifth lens and the sixth lens is 0.120mm, so that the total of all the air gaps on the optical axis between the first lens to the sixth lens is calculated to be 2.4mm, a focal length of the first lens is 55.400mm, a focal length of the second lens is 44.000mm, a focal length of the combined lens is-39.195 mm, a focal length of the fifth lens is 17.347mm, a focal length of the sixth lens is-34.120 mm, a system focal length of the optical lens system is 20.726mm, and an exit pupil distance of the optical lens system is 24.000 mm.