WO2022227541A1 - Optical lens group and head-mounted display device - Google Patents

Abstract

An optical lens group and a head-mounted display device. The optical lens group comprises: a first lens (100), a second lens (200), a quarter-wave plate and a transflective film; the first lens (100) comprises a first surface (110) and a second surface (120) which are oppositely provided; the first lens (100) further comprises a light incident surface (130) and a light exit surface (140) which are oppositely provided, the light incident surface (130) is connected to the first surface (110) and the second surface (120), the light exit surface (140) is connected to the first surface (110) and the second surface (120), light incident by the light incident surface (130) is totally reflected between the first surface (110) and the second surface (120), and the light exit surface (140) is provided with a polarization reflection film; the second lens (200) is provided adjacent to the second surface (120) of the first lens (100); the quarter-wave plate is provided on the side of the second surface (120) of the first lens (100) facing away from the first surface (110); and the transflective film is provided on the side of the quarter-wave plate facing away from the first lens (100). The structure can effectively reduce the volume of the head-mounted display device and facilitates use and wearing of a use.

Description

Optics and Head Mounted Displays technical field

The present invention relates to the technical field of optical display, and in particular, to an optical lens group and a head-mounted display device.

Background technique

Head mounted display device is an electronic product that can provide immersive experience. At present, the display principle of head mounted display device includes Augmented Reality technology, referred to as AR display technology. Internal and external light are superimposed to add a virtual image to the real picture of the outside world.

In order to display and image the light at the position of the human eye, the light needs to have a large enough space in the head-mounted display device to ensure that the head-mounted display device has a sufficient optical path. However, the volume of the head-mounted display device is too large, which is inconvenient for users to wear.

SUMMARY OF THE INVENTION

Based on this, in view of the large volume of the existing head-mounted display device, which is inconvenient for users to use and wear, it is necessary to provide an optical lens group and a head-mounted display device, which aim to reduce the volume of the head-mounted display device and facilitate the user. Use wear.

In order to achieve the above purpose, an optical lens assembly proposed by the present invention, the optical lens assembly includes:

a first lens, the first lens includes a first surface and a second surface arranged oppositely, the first surface and the second surface are parallel to each other, and the first lens also includes a light incident surface and a light exit surface arranged oppositely surface, the light incident surface is connected to the first surface and the second surface, the light exit surface is connected to the first surface and the second surface, and the light exit surface is provided with a polarizing reflection film;

a second lens, the second lens is disposed adjacent to the second surface of the first lens, and the light incident through the light incident surface is totally reflected between the first surface and the second surface;

a quarter wave plate, the quarter wave plate is provided on a side of the second surface of the first lens facing away from the first surface; and

A transflective film, the transflective film is arranged on the side of the quarter wave plate away from the first lens.

Optionally, the light emitting surface is an aspherical surface or a free-form surface.

Optionally, the light emitting surface of the first lens is convex toward a direction away from the second lens.

Optionally, the first surface and the second surface are parallel to each other.

Optionally, the second lens includes a third surface and a fourth surface disposed opposite to each other, the third surface is parallel to the fourth surface, and the third surface faces the first lens;

The area of the light-emitting surface of the first lens corresponding to the second surface is the first area, the area of the third surface is the second area, and the second area is greater than or equal to the first area.

Optionally, the second surface includes a light-receiving area and a non-light-receiving area, the light incident through the light-incident surface is totally reflected between the first surface and the light-receiving area, and the second lens further includes a glue part, the glue part extends from the third surface to the non-light-receiving area, and is glued and connected to the non-light-receiving area.

Optionally, the optical lens group further includes a third lens, the third lens includes a fifth surface and a sixth surface disposed opposite to each other, the quarter-wave plate is disposed on the fifth surface, and the A transflective film is arranged on the sixth surface, the fifth surface of the third lens faces the first lens, the sixth surface faces the second lens, and the third surface of the second lens A groove is opened, and the third lens is glued and arranged in the groove.

Optionally, the sixth surface is an aspherical surface or a free-form surface, and the structure of the cemented position of the sixth surface and the second lens is the same.

Optionally, the transflective film is provided on the third surface of the second lens, and the quarter-wave plate is provided on the surface of the transflective film facing the first lens.

Optionally, the quarter wave plate is arranged on the third surface of the second lens, and the transflective film is arranged on the fourth surface of the second lens.

Optionally, the optical lens group further includes an anti-reflection film, and the anti-reflection film is provided on the fourth surface of the second lens.

Optionally, the optical lens group further includes a fourth lens, the fourth lens is disposed on the light-emitting surface of the first lens, the fourth lens includes a seventh surface and an eighth surface disposed opposite to each other, the The seventh surface is on the same plane as the first surface, and the eighth surface is on the same plane as the second surface.

Optionally, the fourth lens includes a cemented surface facing the first lens, the structure of the cemented surface is the same as the structure of the light-emitting surface of the first lens, and the fourth lens and the first lens Glue settings.

Optionally, the second lens extends toward the eighth surface along the second surface, one end of the second lens is cemented with the first lens, and the other end of the second lens is connected to the first lens. Fourth lens cemented setup.

Optionally, the optical lens group includes a display, the display has a light emitting surface for emitting light, and the included angle between the light emitting surface and the horizontal plane is θ, which satisfies: 30°<θ<70°.

In addition, in order to achieve the above object, the present invention also provides a head-mounted display device, the head-mounted display device includes a housing and an optical lens group as described above, and the optical lens group is provided in the housing.

In the technical solution proposed by the present invention, the light enters through the light incident surface of the first lens, the light first irradiates the first surface of the first lens or the second surface of the first lens, and the incident angle of the light is greater than or equal to At the critical angle of total reflection, the light is emitted from the optically dense medium to the optically sparser medium, the light satisfies the total emission of the light on the first surface or the second surface, and the light is directed to the light-emitting surface of the first lens. The polarized reflective film has a polarization transmission direction. When the light passes through the polarized reflective film for the first time, the polarization direction of the light is different from the transmission direction of the polarized reflective film, and the light is reflected by the polarized reflective film. The reflected light passes through a quarter wave plate, and the linearly polarized light is converted to circularly polarized light. When the circularly polarized light passes through the transflective film, part of the light is reflected and part of the light is transmitted. The rotation direction of the reflected circularly polarized light is reversed, and when the circularly polarized light passes through the quarter-wave plate, the circularly polarized light is converted to linearly polarized light. At this time, the polarization direction of the linearly polarized light is the same as the transmission direction of the polarized reflective film, and the light is transmitted through the polarized reflective film, and is imaged and displayed at the position of the human eye. The technical scheme of the present invention reduces the volume of the optical lens group through the transmission of light in the first lens and the second lens, thereby reducing the volume of the head-mounted display device while ensuring the optical path of the light, which is convenient for users to wear.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a schematic diagram of a light propagation path of an embodiment of an optical lens assembly of the present invention;

Fig. 2 is the structural representation of the optical lens group in Fig. 1;

Fig. 3 is the exploded structure schematic diagram of the optical lens group in Fig. 2;

4 is a schematic structural diagram of another embodiment of the optical lens assembly of the present invention;

Fig. 5 is the modulation transfer function diagram of the optical lens group in Fig. 1;

Fig. 6 is the dot diagram of the optical lens group in Fig. 1;

Fig. 7 is the field curvature and distortion diagram of the optical lens group in Fig. 1;

Fig. 8 is the chromatic aberration diagram of the optical lens group in Fig. 1;

FIG. 9 is a relative illuminance diagram of the optical lens group in FIG. 1 .

Description of reference numbers:

label	name	label		name
100	first lens	310	fifth surface
110	first surface	320	sixth surface
120	second surface	400	fourth lens
130	incident light surface	410	seventh surface
140	light-emitting surface	420	eighth surface
200	second lens	430	glued surface
201	groove	500	monitor
210	third surface	510	light
220	fourth surface	600	human eye position
300	third lens

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

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. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the specific posture changes, the directional indication also changes accordingly.

In addition, descriptions such as "first", "second", etc. in the present invention are only for descriptive purposes, and should not be construed as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, "fixed" may be a fixed connection, a detachable connection, or an integrated; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be an internal communication between two elements or an interaction relationship between the two elements, unless otherwise explicitly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

In the technical field of related head-mounted displays, the AR display device is provided with a light source, and the external light 510 can also enter the interior of the AR display device. to add an image. In order to ensure that the light 510 has enough space for transmission, the volume of the head-mounted display device is too large, thereby causing great inconvenience for the user during the wearing process.

In order to solve the above problems, referring to FIG. 1 to FIG. 3 , the present invention provides an optical lens group, the optical lens group includes: a first lens 100 , a second lens 200 , a quarter-wave plate and a transflective film . The number of lenses included in the optical lens group is not limited to the first lens 100 and the second lens 200, and may include more than two lenses. The refractive index of the optical lens group composed of these optical lenses is n, the dispersion coefficient is v, and satisfies: 1.45<n<1.60, 50<v<75. The first lens 100 and the second lens 200 may be made of optical plastic material, or may be made of optical glass material. The glass material enables the first lens 100 and the second lens 200 to obtain higher optical properties, such as higher transmittance. The optical plastic is easy to process the lens, and the first lens 100 and the second lens 200 can be processed and formed by injection molding. The quarter-wave plate and the transflective film are disposed between the first lens 100 and the second lens 200 . The quarter-wave plate and the transflective film can be independent optical elements or film layer structures. When the quarter-wave plate and the semi-reflective and semi-transparent film are independent optical elements, they are respectively arranged at a certain distance from the first lens 100 and the second lens 200 . When the quarter-wave plate and the semi-reflective and semi-transparent film are in film layer structures, they may be disposed on the surface of the first lens 100 or the surface of the second lens 200 . The setting method can be sticking or coating.

Specifically, the first lens 100 includes a first surface 110 and a second surface 120 disposed oppositely, and the first lens 100 further includes a light incident surface 130 and a light exit surface 140 disposed oppositely. The light incident surface 130 is connected to the first surface 110 and the light exit surface 140. The second surface 120, the light-emitting surface 140 is connected to the first surface 110 and the second surface 120, the light-emitting surface 140 is provided with a polarized reflection film, and the light 510 entering through the light-incident surface 130 is on the first surface 110, which satisfies the condition of total reflection of light , the incident angle is greater than or equal to the critical angle, and the ray 510 is emitted from the optically denser medium to the optically sparser medium. The light ray 510 also satisfies the condition of total reflection of light on the second surface 120 , the incident angle of the light ray 510 is greater than or equal to the critical angle, and the light ray 510 is emitted from the optically denser medium to the optically sparser medium. The light 510 may be directed to the first surface 110 first, and then directed to the second surface 120 . It can also be directed to the second surface 120 first, and then directed to the first surface 110 . That is to say, the inclination direction of the light incident surface 130 may be toward the first surface 110 or toward the second surface 120 , which is set according to the position of the display 500 that emits the light 510 . The polarizing reflective film can be attached to the light-emitting surface 140 , or can be coated on the light-emitting surface 140 .

The second lens 200 is disposed adjacent to the second surface 120 of the first lens 100 , the quarter-wave plate is disposed on the side of the second surface 120 of the first lens 100 away from the first surface 110 , and the transflective film is disposed on the four The one-wave plate faces away from the side of the first lens 100 . The second lens 200 is adjacent to the first lens 100 , which can be understood as a certain gap between the first lens 100 and the second lens 200 , or a partial distance between the first lens 100 and the second lens 200 . In this way, when the light 510 is directed to the second surface 120 , the light 510 satisfies the requirement that the light 510 enters the light sparse medium from the optically dense medium, so as to ensure that the light 510 can be totally reflected and directed to the light-emitting surface 140 of the first lens 100 , so as to avoid the first lens 100 and the second lens 200 are abutted together, and the light 510 is directly emitted from the first lens 100 to the second lens 200 . The thickness of the first lens 100 is between 2 mm and 8 mm, and the thickness of the second lens 200 is less than 3 mm. It can be seen that the combined thickness of the first lens 100 and the second lens 200 is still relatively thin. It should be pointed out that, in this embodiment, the quarter-wave plate and the semi-reflective and semi-transparent film may be disposed on the same surface of the second lens, or may be disposed on two opposite surfaces of the second lens.

In the technical solution proposed in this embodiment, the light 510 enters through the light incident surface 130 of the first lens 100 , and the light 510 first irradiates the first surface 110 of the first lens 100 or irradiates the second surface of the first lens 100 120, the incident angle of the ray 510 is greater than or equal to the critical angle of total reflection, the ray 510 is emitted from the optically denser medium to the optically sparser medium, the ray 510 meets the full emission of the ray 510 on the first surface 110 or the second surface 120, and the ray 510 is emitted. toward the light-emitting surface 140 of the first lens 100 . The polarized reflective film has a polarization transmission direction. When the light 510 passes through the polarized reflective film for the first time, the polarization direction of the light 510 is different from the transmission direction of the polarized reflective film, and the light 510 is reflected by the polarized reflective film. The reflected light 510 passes through a quarter wave plate, and the linearly polarized light is converted into circularly polarized light. When the circularly polarized light passes through the transflective film, part of the light 510 is reflected and part of the light 510 is transmitted. The rotation direction of the reflected circularly polarized light is reversed, and when the circularly polarized light passes through the quarter-wave plate, the circularly polarized light is converted into linearly polarized light. At this time, the polarization direction of the linearly polarized light is the same as the transmission direction of the polarized reflective film, and the light 510 is transmitted through the polarized reflective film, and is imaged and displayed at the position 600 of the human eye. In the technical solution of this embodiment, the light 510 is transmitted in the first lens 100 and the second lens 200 to reduce the volume of the optical lens group, thereby reducing the volume of the head-mounted display device while ensuring the optical path of the light 510 , which is convenient for users to wear.

It should be pointed out that the light 510 emitted by the display 500 is polarized light. If the light 510 emitted by the display 500 is circularly polarized light, a quarter-wave plate is arranged on the light-emitting surface 140 of the display 500 to convert the circularly polarized light into Linearly polarized light. In addition, in order to protect the light emitting surface 140 of the display 500 , a transparent protective plate may also be provided on the light emitting surface 140 of the display 500 . The transparent protective plate can be glued and disposed on the light-emitting surface 140 of the first lens 100 , so as to fix the display 500 on the first lens 100 . The glue setting is glued by UV (Ultraviolet) glue.

In the above embodiment, it can be known that the light 510 is refracted and reflected multiple times between the first lens 100 and the second lens 200 . Among them, some of the light rays 510 are far away from the optical axis, and the optical path is different between positions near the optical axis and positions far away from the optical axis. As a result, it is easy to generate aberrations. In order to reduce the generation of aberrations, the light exit surface 140 is aspherical. Through the design of the aspheric surface of the light emitting surface 140, the curvature radius of the light emitting surface 140 gradually changes from the center position to the edge position, for example, gradually increases, or gradually decreases. Through the gradual change of the radius of curvature, the focus position of the light 510 located at the edge position is adjusted, thereby reducing the generation of aberrations.

In addition, the light emitting surface 140 can also be designed as a free-form surface, and the design of the curvature radius of the free-form surface is more diverse. It can be understood that a free-form surface is a combination of multiple aspheric surfaces, and the free-form surface formed by the combination of multiple aspheric surfaces can reduce aberrations and also reduce the installation space required for setting up multiple aspheric surfaces.

In the above embodiment, the light emitting surface 140 of the first lens 100 is convex toward the direction away from the second lens 200 . Through the convex arrangement, when the light 510 passes through the light emitting surface 140 of the first lens 100 , the light 510 is deflected toward the middle position of the light emitting surface 140 , thereby forming a convergence effect of the light 510 . Then, the light 510 converges toward the position 600 of the human eye, so that the light 510 is focused and imaged at the position 600 of the human eye.

In the above embodiment, the first surface 110 and the second surface 120 are parallel to each other. This facilitates the processing and fabrication of the first lens 100 . In addition, the light is totally reflected between the two mutually parallel surfaces, which can ensure the same incident angle, thus ensuring the effective total reflection of the light between the first surface 110 and the second surface 120 .

In the above embodiment, the quarter-wave plate and the semi-reflective and semi-transparent film are film layer structures, and the quarter-wave plate and the semi-reflective and semi-transparent film are attached to the second lens 200 and disposed. The quarter-wave plate and the semi-reflective and semi-transparent film are disposed corresponding to the light-emitting surface 140 of the first lens 100 . The quarter-wave plate and the semi-reflective and semi-transparent film may be disposed on the surface of the second lens 200 over the entire surface. In order to improve the reflection efficiency of the light 510 , the polarized reflective film can also be fully covered on the light-emitting surface 140 of the first lens 100 . Further, for the utilization efficiency of the light 510, the second lens 200 includes a third surface 210 and a fourth surface 220 arranged opposite to each other, the third surface 210 is parallel to the fourth surface 220, and the third surface 210 faces the first lens 100; The area corresponding to the second surface 120 of the light-emitting surface 140 of a lens 100 is the first area, the area of the third surface 210 is the second area, and the second area is greater than or equal to the first area. Since the quarter-wave plate and the transflective film are attached to the second lens 200 and disposed, the second area can be understood as the area occupied by the quarter-wave plate and the transflective film. The second area is greater than or equal to the first area, so that the area occupied by the quarter-wave plate and the semi-reflective and semi-transparent film can be larger, ensuring that the light 510 reflected by the polarized reflective film can pass through the quarter-wave plate and the semi-transparent film. A reverse semi-permeable membrane, thereby improving the utilization efficiency of the light 510 .

In the above-mentioned embodiment, the second surface 120 includes a light-receiving area and a non-light-receiving area, the light 510 incident through the light incident surface 130 is totally reflected between the first surface 110 and the light-receiving area, and the second lens 200 further includes a gluing portion, The glued portion extends from the third surface 210 to the non-light-receiving area, and is glued and connected to the non-light-receiving area. The light-receiving area can be understood as an area that can be irradiated by the light 510 when the light 510 is totally reflected on the second surface 120 . The non-light-receiving area can be understood as an area where the light 510 cannot reach when the light 510 is totally reflected on the second surface 120 . In order to make the structure of the optical lens group more compact, the second lens 200 and the first lens 100 are glued together by a glue part. The material of the glued portion is the same as the material of the second lens 200 , in order to avoid affecting the total reflection of the light 510 on the second surface 120 . The glued part is connected in the non-light-receiving area. The overall cemented lens, such that the cemented lens group is more compact as a whole, and the structural stability is higher.

Referring to FIG. 1 again, in order to further ensure the imaging effect of the light 510, the optical lens group further includes a third lens 300, and the third lens 300 includes a fifth surface 310 and a sixth surface 320 arranged oppositely, a quarter wave plate Set on the fifth surface 310, the transflective film is set on the sixth surface 320, the fifth surface 310 of the third lens 300 faces the first lens 100, the sixth surface 320 faces the second lens 200, and the first A groove 201 is defined on the three surfaces 210 , and the third lens 300 is glued and disposed in the groove 201 . This embodiment can be applied to the augmented reality technology. The external light 510 passes through the second lens 200 , the third lens 300 and the first incident in sequence, the internal light 510 and the external light 510 are superimposed together, and the image is displayed at the position 600 of the human eye. . The added third lens 300 can complete the correction imaging of the internal light 510 and the external light 510 . The thickness of the third lens 300 is also less than 3 mm, which ensures that the third lens 300 can be embedded in the second lens 200 .

In the above embodiment, in order to reduce the generation of aberrations, the sixth surface 320 is an aspherical surface or a free-form surface. The sixth surface 320 is an aspherical surface. Through the design of the aspherical surface of the sixth surface 320 , the curvature radius of the sixth surface 320 gradually changes from the center position to the edge position, for example, gradually increases, or gradually decreases. Through the gradual change of the radius of curvature, the focus position of the light 510 located at the edge position is adjusted, thereby reducing the generation of aberrations. In addition, the sixth surface 320 can also be designed as a free-form surface, and the design of the curvature radius of the free-form surface is more diverse. It can be understood that a free-form surface is a combination of multiple aspheric surfaces, and the free-form surface formed by the combination of multiple aspheric surfaces can reduce aberrations and also reduce the installation space required for setting up multiple aspheric surfaces. In addition, in order to make the second lens 200 and the third lens 300 cooperate more closely, the structure of the cemented position of the sixth surface 320 and the second lens 200 is the same. In this embodiment, the light 510 can be effectively converged by the combination of the light emitting surface 140 of the first lens 100 and the sixth surface 320 of the third lens 300 , so that the light 510 can be clearly imaged at the position 600 of the human eye. In this embodiment, the optical power of the optical lens group is φ, 0<φ<0.08.

Referring to FIG. 4 , in order to further reduce the volume of the optical lens group, the quarter-wave plate and the semi-reflective and semi-transparent film are both film-layer structures. The quarter-wave plate and the transflective film are disposed on the same surface of the second lens 200 . Specifically, the transflective film is provided on the third surface 210 of the second lens 200 , and the quarter-wave plate is provided on the surface of the transflective film facing the first lens 100 .

In addition, a quarter-wave plate and a semi-reflective and semi-transparent film may also be disposed on two opposite surfaces of the second lens 200, respectively. Specifically, the quarter-wave plate is disposed on the third surface 210 of the second lens 200 , and the transflective film is disposed on the fourth surface 220 of the second lens 200 .

In order to improve the transmittance of the light 510 , the optical lens group further includes an anti-reflection film, and the anti-reflection film is disposed on the fourth surface 220 of the second lens 200 . By setting the anti-reflection film, the passing quantity of the light 510 can be increased. The anti-reflection coating can be in a laminated setting or a coating setting. When pasting the settings, it is simple and easy to complete. When the coating film is installed, the film layer can be made stronger, and the coating film can improve the compactness of the film layer and increase the wear resistance of the anti-reflection film.

In an embodiment of the present application, the optical lens group further includes a fourth lens 400, the fourth lens 400 is disposed on the light exit surface 140 of the first lens 100, and the fourth lens 400 includes a seventh surface 410 and an eighth surface disposed opposite to each other 420 , the seventh surface 410 and the first surface 110 are in the same plane, and the eighth surface 420 and the second surface 120 are in the same plane. It can be said that the thicknesses of the first lens 100 and the fourth lens 400 are the same. In this way, when assembling the optical lens group, the docking of the first lens 100 and the fourth lens 400 is facilitated, and the first lens 100 and the second lens 200 can be formed into one the whole frame. The fourth lens 400 can further perform imaging analysis on the light 510 . The thickness of the first lens 100 is between 2 mm and 8 mm, and the thickness of the fourth lens 400 is also between 2 mm and 8 mm. It can be seen that the thicknesses of the first lens 100 and the fourth lens 400 are both relatively thin. In addition, the first lens 100 , the second lens 200 , the third lens 300 and the fourth lens 400 can all be obtained by processing optical plastics, and the optical material is light in weight, and the optical lens group thus formed can achieve a light and thin effect. The material of the optical plastic can be EP7000 or K26R.

In the above embodiment, in order to further reduce the volume of the optical lens group, the fourth lens 400 includes a cementing surface 430 facing the first lens 100 . The structure of the cementing surface 430 is the same as the structure of the light exit surface 140 of the first lens 100 . The lens 400 is cemented with the first lens 100 . The first lens 100 and the fourth lens 400 are cemented together. Meanwhile, in order to facilitate the cementation of the first lens 100 and the fourth lens 400 , the structure of the cementing surface 430 is the same as that of the light exit surface 140 of the first lens 100 . The structure of the two is the same, which means that the surface structure of the two is the same. For example, if the light-emitting surface 140 of the first lens 100 is an aspherical surface, the cemented surface 430 is also an aspherical surface, and both have the same radius of curvature and the same arc length.

Further, in order to improve the overall strength of the optical lens group, the second lens 200 extends along the second surface 120 to the eighth surface 420, one end of the second lens 200 is cemented with the first lens 100, and the other end of the second lens 200 is The fourth lens 400 is cemented. The second lens 200 is cemented and fixed on the two lenses. On the basis that the first lens 100 and the second lens 200 have been cemented and fixed, the first lens 100 and the fourth lens are further added through the cementation of the second lens 200 400 gluing force position. Thus, the overall strength of the optical lens group is improved.

The surface type of the aspheric surface is calculated by formula. Specifically, the even-order aspheric surface is one of the aspheric surfaces, and the calculation surface formula of the even-order aspheric surface mainly adopts the even-order aspheric surface coefficient. Specifically, the calculation formula is

Among them, z is the coordinate along the optical axis, Y is the radial coordinate, C is the curvature of each optical surface on the optical axis, k is the Coin Constant, and α _i is the even-order aspheric surface of each high-order term Coefficient, 2i is the order of the aspherical coefficient (The order of Aspherical Coefficient), N is the number of value points. For example α _i includes α ₁ , α ₂ and α ₃ .

Table 1 of the specific parameters of the even-order aspheric surface of the embodiment in FIG. 1 .

Table I

Table 2 of the specific parameters of the even-order aspheric surface of the embodiment in FIG. 2 .

Table II

In the above embodiment, the optical lens group includes a display, the display has a light emitting surface for emitting light, and the angle between the light emitting surface and the horizontal plane is θ, which satisfies: 30°<θ<70°. The included angle θ is set between 30° and 70°, which can ensure that the incident angle of the light passing through the light exit surface of the first lens is greater than or equal to the critical angle of total reflection, thereby ensuring that the first light radiates to the second incident area. The horizontal plane can be understood as the ground on which the user normally stands when wearing the head-mounted display device provided with the optical lens group, and can also be understood as the sea level, or the placement surface when the head-mounted display device is placed stationary.

Fig. 5 is the modulation transfer function diagram of the optical lens group of the present invention, namely the MTF (Modulation Transfer Function) diagram. The MTF diagram is used to refer to the relationship between the modulation degree and the number of line pairs per millimeter in the image, and is used to evaluate the restoration of the details of the scene. Capability; the top black solid line is a theoretically aberration-free curve, and the closer to the black solid line, the better the imaging quality.

Figure 6 is a dot diagram of the optical lens assembly of the present invention; the dot diagram means that after many rays emitted from one point pass through the optical components, the intersections with the image plane are no longer concentrated at the same point due to aberrations, and a single point is formed. Dispersion patterns scattered in a certain range are used to evaluate the imaging quality of the projection optical system. The smaller the root mean square radius value and the geometric radius value, the better the imaging quality. The arrangement order of areas 1 to 6 is from left to right and from top to bottom.

7 is a field curvature and distortion diagram of the optical lens assembly of the present invention, wherein the field curvature refers to the curvature of the image field, which is mainly used to indicate the degree of misalignment between the intersection point of the entire light beam and the ideal image point in the optical assembly. Distortion refers to the aberration of different parts of the object having different magnifications when the object is imaged through optical components. Distortion will cause the similarity of the object image to deteriorate, but it does not affect the image clarity.

Fig. 8 is a chromatic aberration diagram of the optical lens set of the present invention, wherein the vertical axis chromatic aberration is also called magnification chromatic aberration, which mainly refers to a polychromatic chief ray on the object side. Due to the dispersion of the refraction system, it becomes Multiple rays.

9 is a relative illuminance diagram of the optical lens assembly of the present invention. The illuminance value measured in one viewing angle direction reflects the brightness of the optical component imaging. Generally, the central brightness is high and the peripheral brightness is low.

The present invention also provides a head-mounted display device. The head-mounted display device includes a casing and an optical lens group as described above, and the optical lens group is provided in the casing. The optical lens group can be arranged in the casing, or the optical lens group can be wrapped in a half-pack. Through the protection of the shell, it can also play the role of ash and waterproof.

For the specific implementation of the head-mounted display device, reference may be made to the embodiment of the optical lens group, which is not repeated here.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structure transformation made by the contents of the description and drawings of the present invention, or directly/indirectly applied to other All relevant technical fields are included in the scope of patent protection of the present invention.

Claims (16)

1. An optical lens group, characterized in that the optical lens group comprises:

   a first lens, the first lens includes a first surface and a second surface arranged oppositely, the first lens further includes a light incident surface and a light exit surface arranged oppositely, the light incident surface is connected to the first surface and the second surface, the light exit surface is connected to the first surface and the second surface, the light exit surface is provided with a polarized reflection film, and the light entering through the light entrance surface is on the first surface and total reflection between the second surface;

   a second lens, the second lens is disposed adjacent to the second surface of the first lens;

   a quarter wave plate, the quarter wave plate is provided on a side of the second surface of the first lens facing away from the first surface; and

   A transflective film, the transflective film is arranged on the side of the quarter wave plate away from the first lens.
2. The optical lens assembly according to claim 1, wherein the light emitting surface is an aspheric surface or a free-form surface.
3. The optical lens assembly of claim 1, wherein the light emitting surface of the first lens is convex toward a direction away from the second lens.
4. The optical lens group according to any one of claims 1 to 3, wherein the first surface and the second surface are parallel to each other.
5. The optical lens assembly according to any one of claims 1 to 3, wherein the second lens comprises a third surface and a fourth surface disposed opposite to each other, and the third surface is parallel to the fourth surface , the third surface faces the first lens;

   The area of the light-emitting surface of the first lens corresponding to the second surface is the first area, the area of the third surface is the second area, and the second area is greater than or equal to the first area.
6. The optical lens assembly of claim 5, wherein the second surface includes a light-receiving area and a non-light-receiving area, and the light incident through the light-incident surface is between the first surface and the light-receiving area. The second lens further includes a glue part, the glue part extends from the third surface to the non-light-receiving area, and is glued and connected to the non-light-receiving area.
7. The optical lens group according to claim 6, wherein the optical lens group further comprises a third lens, the third lens comprises a fifth surface and a sixth surface arranged oppositely, the quarter wave The sheet is arranged on the fifth surface, the transflective film is arranged on the sixth surface, the fifth surface of the third lens faces the first lens, and the sixth surface faces the second lens A lens, the third surface of the second lens is provided with a groove, and the third lens is glued and arranged in the groove.
8. 8. The optical lens assembly of claim 7, wherein the sixth surface is an aspherical surface or a free-form curved surface, and the sixth surface and the second lens have the same cementing position structure.
9. The optical lens assembly of claim 6, wherein the transflective film is provided on the third surface of the second lens, and the quarter-wave plate is provided on the transflective film The film faces the surface of the first lens.
10. The optical lens assembly of claim 6, wherein the quarter-wave plate is disposed on the third surface of the second lens, and the semi-reflective and semi-transparent film is disposed on the second lens. fourth surface.
11. The optical lens assembly according to claim 5, wherein the optical lens assembly further comprises an anti-reflection film, and the anti-reflection film is provided on the fourth surface of the second lens.
12. The optical lens assembly according to claim 5, wherein the optical lens assembly further comprises a fourth lens, the fourth lens is disposed on the light emitting surface of the first lens, and the fourth lens includes an opposite lens. The seventh surface and the eighth surface are in the same plane as the first surface, and the eighth surface and the second surface are in the same plane.
13. The optical lens assembly according to claim 12, wherein the fourth lens comprises a cemented surface facing the first lens, and the structure of the cemented surface is the same as that of the light exit surface of the first lens, The fourth lens is cemented with the first lens.
14. The optical lens assembly of claim 13, wherein the second lens extends along the second surface toward the eighth surface, and one end of the second lens is cemented with the first lens, The other end of the second lens is cemented with the fourth lens.
15. The optical lens assembly according to any one of claims 1 to 3, wherein the optical lens assembly comprises a display, the display has a light emitting surface for emitting light, and a space between the light emitting surface and the horizontal surface is If the included angle is θ, it satisfies: 30°<θ<70°.
16. A head-mounted display device, characterized in that, the head-mounted display device comprises a casing and the optical lens group according to any one of claims 1 to 15, wherein the optical lens group is provided in the casing.

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