CN218413066U - Optical module and head-mounted display equipment - Google Patents

Abstract

The utility model provides an optical module and a head-mounted display device; the optical module comprises a first lens, a movable lens and a display in sequence along the same optical axis; the movable lens is configured to be movable along the optical axis to approach or move away from the display; the optical module further comprises a light splitting element, a first phase retarder and a polarization reflecting element, wherein the first phase retarder is positioned between the light splitting element and the polarization reflecting element; the light splitting element is arranged on the surface of the movable lens close to the display, and the first phase retarder and the polarization reflecting element are arranged on any side of the first lens; the optical module further comprises a lens group, the lens group is located between the light splitting element and the display, the lens group at least comprises a second lens, the minimum distance between the movable lens and the display is L, and L is larger than or equal to 2mm. The utility model discloses an optical module is zooming the in-process, can guarantee that optical module's angle of vision is unchangeable.

Description

Optical module and head-mounted display equipment

Technical Field

The embodiment of the utility model provides a relate to optical imaging technical field, more specifically, the embodiment of the utility model relates to an optical module and head-mounted display device.

Background

In order to meet the watching requirements of users with different visual degrees such as myopia and hyperopia, the users generally need to additionally wear lenses to obtain clear pictures when using virtual reality equipment, so that the burden of eyes of the users can be increased, the users are not convenient enough when using the virtual reality equipment, and the wearing experience is reduced.

In the prior art, diopter adjustment can be realized by moving the lens in the virtual reality imaging system, but in the process of realizing zooming, the angle of view of the virtual reality imaging system changes, for example, the angle of view before zooming is 90 °, the angle of view after zooming is 80 °, and the difference easily causes aberration, distortion and the like. In addition, the smaller the volume of the virtual reality device, which is usually collocated with a small-sized display, the smaller the size of the display, the smaller the pixel size, the higher the requirement for the size of the foreign object on the surface (the higher the requirement for being closer to the screen), the movement of the lens may cause some foreign objects to fall off, and the visual experience effect may be affected when the lens falls on the display.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an optical module and head-mounted display device's new technical scheme, the optical module field angle can not change around zooming, and the foreign matter that produces when the lens removes can not fall on the display and influence user's visual experience effect simultaneously.

In a first aspect, the present invention provides an optical module comprising, along a same optical axis, a first lens, a movable lens, and a display; wherein the movable lens is configured to be movable along the optical axis to approach or move away from the display;

the optical module further comprises a light splitting element, a first phase retarder and a polarization reflecting element, wherein the first phase retarder is positioned between the light splitting element and the polarization reflecting element; the light splitting element is arranged on the surface of the movable lens close to the display, and the first phase retarder and the polarization reflecting element are arranged on any side of the first lens;

the optical module further comprises a lens group, the lens group is located between the light splitting element and the display, the lens group at least comprises a second lens, the minimum distance between the movable lens and the display is L, and L is larger than or equal to 2mm.

Optionally, the movable lens is a diopter adjustment lens, and the range of translation of the movable lens along the optical axis is 0-5 mm.

Optionally, when the movable lens moves to the extreme position far away from the display, the distance between the surface of the movable lens far away from the display and the surface of the first lens close to the display is L ₁ ，L ₁ ＞0.2mm。

Optionally, when the movable lens moves to the extreme position close to the display, the distance between the surface of the movable lens close to the display and the surface of the second lens far from the display is L ₂ ，L ₂ ＞0.2mm。

Optionally, the display is less than 2 inches in size.

Optionally, the second lens has a center thickness T ₂ ，1mm＜T ₂ < 6mm, the second lens having an optical power of

Optionally, the movable lens has a center thickness of T ₀ ，3mm＜T ₀ < 8mm, the optical power of the movable lens being

Optionally, the optical module further includes a polarizer, the polarization reflection element and the first phase retarder are sequentially stacked to form a first composite film, and the first composite film is disposed on a surface of the first lens close to the display.

Optionally, the first phase retarder is disposed on a surface of the movable lens away from the display;

the optical module further comprises a polarizing element, the polarizing element and the polarization reflecting element are stacked to form a second composite film layer, and the second composite film layer is arranged on the surface, close to the display, of the first lens.

Optionally, the display is configured to emit circularly polarized light or linearly polarized light;

when the light emitted by the display is linearly polarized light, a second phase retarder is arranged on the light emitting side of the display and used for converting the linearly polarized light into the circularly polarized light.

In a second aspect, the present invention provides a head-mounted display device, which includes:

a housing; and

an optical module as described above.

According to the embodiment of the utility model, an optical module is provided, and the optical module is a folding light path, and the light splitting element is directly arranged on the surface of the movable lens close to the display, so that the field angle of the optical module is hardly changed in the process of realizing zooming, thereby avoiding adverse phenomena such as aberration and image distortion, and improving the experience of users with different visual degrees; and at least one lens is added between the display and the movable lens, and the distance between the movable lens and the display is restrained, so that the adverse effect of foreign matters introduced in the moving process of the movable lens on the visual experience can be eliminated.

Other features of the present description and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and together with the description, serve to explain the principles of the specification.

Fig. 1 is a schematic structural diagram of an optical module according to embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of an in-use configuration of the optical module shown in FIG. 1;

FIG. 3 is a schematic diagram of another usage status of the optical module shown in FIG. 1;

FIG. 4 is a schematic view of the first lens surface of FIG. 1 with a composite film layer;

FIG. 5 is a dot-sequence diagram of the optical module shown in FIG. 1;

FIG. 6 is a graph of MTF for the optical module shown in FIG. 1;

FIG. 7 is a distortion diagram of the optical module shown in FIG. 1;

FIG. 8 is a vertical axis chromatic aberration diagram of the optical module shown in FIG. 1;

fig. 9 is a schematic structural view of an optical module according to embodiment 2 of the present invention;

FIG. 10a is a schematic diagram of the first lens of FIG. 9 with a film layer disposed near the surface of the display;

FIG. 10b is a diagram of the movable lens of FIG. 9 with a film disposed away from the surface of the display;

FIG. 11 is a structural diagram of the optical module shown in FIG. 9 in a use state;

FIG. 12 is a schematic view of another usage state of the optical module shown in FIG. 9;

FIG. 13 is a dot-line diagram of the optical module shown in FIG. 9;

FIG. 14 is a graph of MTF for the optical module shown in FIG. 9;

FIG. 15 is a distortion diagram of the optical module shown in FIG. 9;

FIG. 16 is a vertical axis aberration diagram of the optical module shown in FIG. 9;

fig. 17 is a schematic structural view of an optical module according to embodiment 3 of the present invention;

FIG. 18 is a structural diagram of the optical module shown in FIG. 17 in a use state;

FIG. 19 is a schematic view of another usage state of the optical module shown in FIG. 17;

FIG. 20 is a dot diagram of the optical module shown in FIG. 17;

FIG. 21 is a graph of MTF for the optical module shown in FIG. 17;

FIG. 22 is a distortion diagram of the optical module shown in FIG. 17;

FIG. 23 is a vertical axis chromatic aberration diagram of the optical module shown in FIG. 17.

Description of reference numerals:

10. a first lens; 11. a first surface; 12. a second surface; 20. a movable lens; 21. a third surface; 22. a fourth surface; 30. a second lens; 31. a fifth surface; 32. a sixth surface; 40. A display; 50. a light-splitting element; 60. a first phase retarder; 70. a polarizing reflective element; 80. A polarizing element; 91. a first anti-reflection film; 92. a second anti-reflection film; 93. a first composite film layer; 94. a second composite film layer; 01. the human eye.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: unless specifically stated otherwise, the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be considered a part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to the utility model discloses an aspect provides an optical module, optical module can be fit for being applied to Head mounted display device (HMD), for example VR Head mounted device. Wherein, VR head-mounted device can include VR glasses or VR helmet etc. the embodiment of the utility model provides a do not specifically limit this.

The embodiment of the utility model provides an optical module, as shown in FIG. 1, optical module includes along same optical axis in proper order: a first lens 10, a movable lens 20, and a display 40; the movable lens 20 is configured to be movable along the optical axis to approach or move away from the display 40;

the optical module further comprises a light splitting element 50, a first phase retarder 60 and a polarization reflection element 70, wherein the first phase retarder 60 is located between the light splitting element 50 and the polarization reflection element 70; the light splitting element 50 is disposed on the surface of the movable lens 20 close to the display 40, and the first phase retarder 60 and the polarization reflection element 70 are disposed on either side of the first lens 10;

the optical module further comprises a lens group, the lens group is located between the light splitting element 50 and the display 40, the lens group at least comprises one second lens 30, the minimum distance between the movable lens 20 and the display 40 is L, and L is larger than or equal to 2mm.

The utility model discloses optical module, it is a folding light path structure, as shown in FIG. 1, has introduced at least one second lens 30 between display 40 and portable lens 20, has retrained the minimum interval between portable lens 20 and the display 40 simultaneously and is for being more than or equal to 2mm. In fact, some foreign objects may inevitably fall off during the process of moving the movable lens 20 to achieve zooming (or diopter adjustment), and the movable lens 20 and the display 40 are spaced by the at least one second lens 30 and the distance range between the two is limited, so that the foreign objects can be prevented from directly falling on the display 40, thereby eliminating the adverse effect on the visual experience caused by the foreign objects introduced by the movement of the movable lens 20, and being beneficial to improving the imaging quality. Can make the user of different degrees of vision all can obtain good visual experience effect when not wearing extra lens after the degree of vision is adjusted, and different user's visual experience difference is less.

In the embodiment of the present application, the light splitting element 50 is disposed on a surface (see the third surface 21 shown in fig. 1) of the movable lens 20 close to the display 40, so that during the movement of the movable lens 20 to achieve zooming, the light splitting element 50 moves in translation along with the movable lens 20, and the angle of view of the optical module is hardly changed.

However, in the related art, the transflective film is not attached to the movable lens, so that the field angle of the optical module changes during the process of moving the lens to realize zooming, for example, the field angle before zooming is 90 ° and the field angle after zooming is 80 °. This can cause aberrations, distortion, etc. that users of different degrees of vision experience as they do.

In the embodiment of the present application, the movable lens 20 can perform a translational motion along the optical axis of the optical module to achieve a near-sighted or far-sighted diopter adjustment function.

For example, as shown in fig. 1 and 2, when the movable lens 20 moves to the left along the optical axis, the movable lens 20 moves away from the display 40, and the diopter adjustment for myopia can be realized by controlling the movement range.

For example, as shown in fig. 1 and 3, when the movable lens 20 moves rightward along the optical axis, the movable lens 20 approaches the display 40, and diopter adjustment for distance vision can be performed by controlling the movement range.

In the optical module of the embodiment of the present application, the movable lens 20 is a lens where the light splitting element 50 is located, and at least one additional lens, such as the second lens 30 described above, is added between the light splitting element 50 and the display 40, while the minimum distance between the movable lens 20 and the display 40 is constrained to be greater than or equal to 2mm. In this way, the angle of view of the optical module is approximately constant during zooming by moving the movable lens 20; meanwhile, it is possible to prevent a foreign object caused when the movable lens 20 moves from falling on the display 40 to adversely affect the visual effect.

The optical module of the embodiment of the present invention, as shown in fig. 1, is formed with a folding light path near one side of the human eye 01. The folded optical path includes, for example, two lenses, a first lens 10 and a movable lens 20 shown in fig. 1; meanwhile, the optical module further includes a beam splitting element 50, a first phase retarder 60 and a polarization reflection element 70 disposed between the two lenses, as shown in fig. 4.

It should be noted that, in the above-mentioned folded optical path, the number of lenses includes, but is not limited to, two, and the number of the first lenses 10 can be flexibly adjusted according to specific needs. With the increase of the number of lenses in the optical module, although the imaging quality of the optical module can be improved, the size of the optical module along the optical axis direction may be affected, resulting in a larger volume and increased weight of the optical module.

The embodiment of the utility model provides an in, consider factors such as optical module's volume, weight, formation of image quality and manufacturing cost, designed in the folding light path of constitution and contained two lenses. The position of the first lens 10 is relatively fixed, and the position of the movable lens 20 in the optical module is not fixed, and it can perform a translational motion along the optical axis to approach or move away from the display 40, so that zooming, i.e. diopter adjustment, can be achieved. The optical module can be suitable for groups with different visual degrees, and good visual experience can be obtained.

The optical module according to the embodiment of the present invention is a folded optical path, which includes the first lens 10, the movable lens 20, the at least one second lens 30 and the display 40; the optical module further includes optical elements such as a beam splitter element 50, a first phase retarder 60, and a polarization reflection element 70, and these optical elements (optical films) can be used to form a folded optical path between the first lens 10 and the movable lens 20, so that the light is folded back therein, which is beneficial to the final clear imaging.

The light splitting element 50 is, for example, a transflective film.

The light splitting element 50 allows a portion of the light to transmit and another portion of the light to reflect.

It should be noted that the reflectivity of the light splitting element 50 can be flexibly adjusted according to specific needs, which is not limited in the embodiment of the present invention.

The first phase retarder 60 is, for example, a quarter-wave plate. Of course, other phase retarders may be provided as desired.

In the folded optical path on the side near the human eye 01, a first phase retarder 60 may be used to change the polarization state of the light in the folded optical path. For example, for converting linearly polarized light into circularly polarized light, or for converting circularly polarized light into linearly polarized light.

The polarizing reflective element 70 is, for example, a polarizing reflective film.

The polarization reflection element 70 is a polarization reflector for horizontally linearly polarized light reflection and vertically linearly polarized light transmission, or any other polarization reflector for linearly polarized light reflection at a specific angle and linearly polarized light transmission in the direction perpendicular to the angle.

In an embodiment of the present invention, the first phase retarder 60 and the polarization reflective element 70 are used to resolve the light and transmit the light. The polarization reflection element 70 has a transmission axis, and an included angle between the transmission axis direction of the polarization reflection element 70 and the fast axis or the slow axis of the first phase retarder 60 is 45 °.

It should be noted that the arrangement positions of the light splitting element 50, the first phase retarder 60, and the polarization reflection element 70 between the first lens 10 and the movable lens 20 are flexible, but it is necessary to ensure that the first phase retarder 60 is located between the light splitting element 50 and the polarization reflection element 70.

In the embodiment of the present application, the light splitting element 50 is disposed on a surface of the movable lens 20 close to the display 40. Both the first phase retarder 60 and the polarization reflective element 70 may be disposed at appropriate positions between the movable lens 20 and the first lens 10 such that the light splitting element 50 and the first phase retarder 60 are spaced apart by the movable lens 20.

As shown in fig. 1, the light propagates through the optical module as follows:

light emitted from the light-emitting surface of the display 40 is transmitted through the second lens 30 and the movable lens 20, reflected by a surface (the first surface 11 shown in fig. 1) of the first lens 10 close to the movable lens 20, transmitted by a surface (the fourth surface 22 shown in fig. 1) of the movable lens 20 close to the first lens 10, reflected by a surface (the third surface 21 shown in fig. 1) of the movable lens 20 close to the second lens 30, transmitted by the surface (the fourth surface 22 shown in fig. 1) of the movable lens 20 close to the first lens 10 and the first lens 10, and finally emitted light is incident on the human eye 01 for imaging.

The utility model discloses optical module, it is a folding light path optical structure design, as shown in FIG. 1, each optical lens piece and optical element in the optical module can arrange and lie in same optical axis according to the mode of setting for. The size of the whole light path structure is small, and the whole light path structure does not occupy large space. The wearable display device is very suitable for being applied to intelligent wearable devices such as a head-mounted display device.

According to the embodiment of the present invention, the optical module is a folded optical path structure, the optical module is a folded optical path, the light splitting element 50 is directly disposed on the surface of the movable lens 20 close to the display 40, and the field angle of the optical module hardly changes in the process of zooming, so that adverse phenomena such as aberration and image distortion can be avoided, and the experience of users with different visual degrees can be improved; and, at least one lens is added between the display 40 and the movable lens 20 while restricting the distance between the movable lens 20 and the display 40, so that the bad influence of foreign matters introduced during the movement of the movable lens 20 on the visual experience can be eliminated.

In some examples of the present invention, the movable lens 20 is a diopter adjusting lens, and the movable lens 20 is disposed along the optical axis in a translational range of 0-5 mm.

The utility model discloses an among the optical module, designed a movable lens 20, it is the diopter adjusting lens, through this movable lens 20 of following the optical axis translation in the light path and control the amount of movement, can make movable lens 20 be close to or keep away from display 40 to realize near-sighted or the diopter of farsighted and adjust. Like this, when the user is using optical module, myopic or farsighted user need not additionally to wear the lens of correcting eyesight, can adjust movable lens 20's displacement range as required to all can watch clear, complete formation of image picture.

For example, as shown in fig. 1 to 3, in the optical module, the movable lens 20 is moved left and right along the optical axis, and the range of the left and right movement may be set to 0 to 5mm, thereby achieving the visual power adjustment from 500 degrees for near vision to 200 degrees for far vision.

Of course, the scope that removes about also can adjusting movable lens 20 along the optical axis as required to realize the myopia or the hyperopia diopter of bigger number of degrees and adjust, the utility model discloses in do not limit this.

Optionally, as shown in fig. 1 and 2, when the movable lens 20 moves to the extreme position far away from the display 40, the distance between the surface of the movable lens 20 far away from the display 40 and the surface of the first lens 10 close to the display 40 is L ₁ ，L ₁ ＞0.2mm。

For example, as shown in fig. 2, the movable lens 20 is moved to the leftmost side, that is, the movable lens 20 is moved to an extreme position far from the display 40, at which time, the distance between the two surfaces where the movable lens 20 and the first lens 10 are close to should be controlled to be > 0.2mm, and thus, refractive adjustment of 500 degrees of myopia can be achieved. So that a user with 500 degrees of myopia can clearly and completely see the imaging picture without wearing glasses.

Optionally, as shown in fig. 1 and 3, when the movable lens 20 moves to the extreme position close to the display 40, the distance between the surface of the movable lens 20 close to the display 40 and the surface of the second lens 30 far from the display 40 is L ₂ ，L ₂ ＞0.2mm。

For example, as shown in fig. 3, the movable lens 20 is moved to the rightmost side, that is, the movable lens 20 is moved to the extreme position near the display 40, and at this time, the distance between the two surfaces near the movable lens 20 and the second lens 30 should be controlled to be > 0.2mm, so that the dioptric adjustment of far vision 200 degrees can be realized. So that a user who has far vision at 200 degrees can clearly and completely see the imaged picture without wearing glasses.

According to the optical module, users with different visual degrees can watch clear and complete imaging pictures through diopter adjustment, and the difference of the images watched among different users is small.

In some examples of the present application, the display 40 is less than 2 inches in size.

In order to realize a small-sized and lightweight imaging system for a virtual reality device, a display having a small size needs to be used. The smaller the size of the virtual reality imaging system, the more sensitive it is to foreign objects, especially in a position close to the display, the diopter adjustment is achieved by movement of the lens, and if the movable lens is arranged close to the display, the foreign objects generated by the movement of the lens may affect the visual experience.

The utility model discloses optical module, through increase a second lens 30 between portable lens 20 and display 40, restrain portable lens 20 and display 40's interval simultaneously and eliminate the influence that portable lens 20 removed the foreign matter of introducing and brought.

In order to reduce the size and weight of the optical module, the present invention employs a very small size display 40. The size of the display 40 is, for example, less than 2 inches.

However, for smaller displays, the smaller the pixel size, the higher the foreign object size requirement (the closer the movable lens 20 is to the display 40) on its surface. Some foreign objects falling off during the movement of the movable lens 20 may be generated, and the falling off onto the surface of the display 40 may affect the experience. The optical module scheme of the embodiment of the application can completely avoid the defect problem caused by a small-size display.

In some examples of the present invention, the second lens 30 has a center thickness T ₂ ，1mm ＜T ₂ < 6mm, the second lens 30 having an optical power of

The second lens 30 has positive focal power, and can function to collect light.

It should be noted that the second lens 30 can be used to separate the display 40 from the movable lens 20, and at the same time, can restrict the distance between the display 40 and the movable lens 20. The number of the second lenses 30 can be adjusted as desired, including but not limited to one.

Optionally, the second lens 30 comprises a fifth surface 31 close to the display 40 and a sixth surface 32 far from the display 40, the fifth surface 31 and the sixth surface 32 being aspheric or planar.

Alternatively, the antireflection films are attached to both surfaces of the second lens 30, respectively.

In some examples of the present invention, the movable lens 20 has a center thickness T ₀ ， 3mm＜T ₀ < 8mm, the movable lens 20 having an optical power of

The movable lens 20 can be used to realize diopter adjustment, that is, a zoom function, and the position of the movable lens 20 in the optical module is not fixed, but can be moved in a left-right translational manner along the optical axis.

The movable lens 20 may include a third surface 21 proximate to the display 40 and a fourth surface 22 distal to the display 40. Wherein the third surface 21 and the fourth surface 22 may be aspheric surfaces or planar surfaces.

The light splitting element 50 may be attached to the third surface 21 by a coating or an optical adhesive.

Alternatively, an anti-reflection film may be attached on the fourth surface 22 of the movable lens 20.

The anti-reflection film can be formed on the optical component in a film coating mode to form interfaces, so that the transmittance is increased, the reflectivity is reduced, the image distortion is reduced, and a user can enjoy clearer image quality to reduce the phenomenon of glare.

In some examples of the present invention, the first lens 10 has a center thickness T ₁ ，3mm ＜T ₁ < 6mm, the first lens 10 having an optical power of

Optionally, the first lens 10 includes a first surface 11 close to the display 40 and a second surface 12 far from the display 40, and the first surface 11 and the second surface 12 may be aspheric, for example.

In some examples of the present invention, as shown in fig. 1 and 4, the optical module further includes a polarization element 80, the polarization reflection element 70 and the first phase retarder 60 are sequentially stacked to form a first composite film 93, and the first composite film 93 is disposed on a surface of the first lens 10 close to the display 40 (i.e., the first surface 11 shown in fig. 1).

Optionally, the first composite film layer 93 may further include a first anti-reflection film 91, and the first anti-reflection film 91 is sequentially stacked on the first phase retarder 60, the polarization reflection element 70, and the polarization element 80; wherein, the first anti-reflection film 91 is adhered to the first surface 11 by optical glue. Meanwhile, an antireflection film may also be attached on the second surface 12 of the first lens 10.

The polarizing element 80 can be used to reduce stray light.

The anti-reflection film can be formed on the optical element in a film coating mode to form interfaces, so that the transmittance is increased, the reflectivity is reduced, the image distortion is reduced, and a user can enjoy clearer image quality to reduce the phenomenon of glare.

In some examples of the present invention, as shown in fig. 9, 10a, 10b and 17, the first phase retarder 60 is disposed on a surface of the movable lens 20 away from the display 40; the optical module further comprises a polarizer 80, the polarizer 80 and the polarization reflection element 70 are stacked to form a second composite film 94, and the second composite film 94 is disposed on a surface of the first lens 10 close to the display 40.

That is, the polarization reflective element 70 and the first phase retarder 60 may be attached together and then disposed on the surface of the first lens 10 on the side close to the human eye 01. Of course, the polarization reflective element 70 and the first phase retarder 60 may be disposed at an interval.

In some examples of the present invention, the display 40 is configured to emit circularly polarized light or linearly polarized light; when the light emitted from the display 40 is linearly polarized light, a second phase retarder is disposed on a light emitting side of the display 40, and the second phase retarder is configured to convert the linearly polarized light into circularly polarized light.

For example, the light emitting surface of the display 40 is provided with a protective glass.

Alternatively, the second phase retarder may be disposed on the light emitting surface of the display 40, or disposed at a suitable position between the display 40 and the second lens 30, or disposed at a suitable position close to the light emitting surface of the display 40.

Optionally, the refractive index n ranges of the first lens 10, the movable lens 20, and the second lens 30 are: n is more than 1.4 and less than 1.7; the first lens 10, the movable lens 20, and the second lens 30 have an abbe number v ranging from: v is more than 20 and less than 75. The refractive index and the dispersion coefficient of the three lenses are adjusted to be matched, so that the imaging quality of the optical module can be improved.

In a specific example of the present invention, the refractive index of the first lens 10 is 1.54, and the abbe number is 55.7; the refractive index of the movable lens 20 is 1.54, and the abbe number is 56.3; the refractive index of the second lens 30 is 1.64 and the abbe number is 23.

The optical module according to the embodiments of the present invention is described in detail by three embodiments.

Example 1

As shown in fig. 1, the optical module includes a first lens 10, a movable lens 20, a single-chip second lens 30 and a display 40 sequentially arranged along the same optical axis; wherein, the first lens 10 comprises a first surface 11 close to the display 40 and a second surface 12 far away from the display 40; the movable lens 20 comprises a third surface 21 proximate to the display 40 and a fourth surface 22 distal to the display 40; the second lens 30 comprises a fifth surface 31 close to the display 40 and a sixth surface 32 far from the display 40;

a light-splitting element 40 on the third surface 21 of the movable lens 20 and an anti-reflection film on the fourth surface 22 of the movable lens 20;

as shown in fig. 4, a first anti-reflection film 91, a first phase retarder 60, a polarization reflection element 70, and a polarization element 80 (forming a first composite film layer 93) are sequentially stacked on a first surface 11 of the first lens 10, and an anti-reflection film is disposed on a second surface 12 of the first lens 10.

In the optical module of embodiment 1, the movable lens 20 can be moved in the direction of the optical axis away from the display 40, such as the left side movement shown in fig. 2, to achieve diopter adjustment of 500 degrees of myopia. The movable lens 20 is also movable in the direction of optical axis approaching the display 40, as shown to the right in fig. 3, to achieve diopter adjustment for distance vision of 200 degrees.

Table 1 shows the optical parameters of each lens in the optical module provided in example 1.

TABLE 1

As shown in fig. 1, the light rays travel as follows:

the display 40 emits circularly polarized light, which is transmitted through the second lens 30 and the movable lens 20, and is changed into linearly polarized light (S light) by the first phase retarder 60 on the first surface 11 of the first lens 10, reflected by the polarization reflection element 70, changed into circularly polarized light by the first phase retarder 60, reflected by the third surface 21 of the movable lens 20, changed into linearly polarized light (P light) by the first phase retarder 60 on the first surface 11 of the first lens 10, and transmitted through the first lens 10 to be projected into the human eye 01.

With respect to the optical module provided in embodiment 1 above, the movable lens 20 can move left and right. The optical performance of the optical module can be shown in fig. 5 to 8:

fig. 5 is a MTF curve graph of an optical module according to embodiment 1 of the present invention, fig. 6 is a schematic view of a dotted diagram of an optical module according to embodiment 1 of the present invention, fig. 7 is a distortion graph of a field curvature according to embodiment 1 of the present invention, and fig. 8 is a vertical axis chromatic aberration diagram according to embodiment 1 of the present invention.

The MTF graph is a modulation transfer function graph, and the imaging definition of the optical module is represented by the contrast of black and white line pairs. As shown in FIG. 5, MTF in this example 1 is >0.6 at 40lp/mm, and the image is clear.

The point alignment chart means that after a plurality of light rays emitted from one point pass through the optical module, intersection points of the light rays and an image surface are not concentrated on the same point any more due to aberration, so that a dispersion pattern scattered in a certain range is formed, and the dispersion pattern can be used for evaluating the imaging quality of the optical module. As shown in fig. 6, in the present embodiment 1, the maximum value of the image points in the dot array image corresponds to the maximum field of view, and the maximum value of the image points in the dot array image is smaller than 22 μm.

The distortion map reflects the difference of the image plane positions of the clear images of different fields, and in the embodiment 1, as shown in fig. 7, the distortion occurs in 1 field at maximum, and the absolute value is less than 30%.

The vertical axis chromatic aberration is also called as magnification chromatic aberration, and mainly refers to the difference of focal positions of blue light and red light on an image surface when a polychromatic main light of an object side is emitted to an image side and becomes a plurality of light rays due to chromatic dispersion of a refraction system. In embodiment 1, as shown in fig. 8, the maximum color difference value of the optical module is less than 190 μm.

Example 2

The optical module provided in embodiment 2, as shown in fig. 9, can be distinguished from the optical module provided in embodiment 1 by the following differences as shown in fig. 10a and 10 b: the first phase retarder 60 is disposed on the fourth surface 22 of the movable lens 20 away from the display 40, and a second anti-reflection film 92 is disposed between the first phase retarder 60 and the fourth surface 22 of the movable lens 20; the polarizing element 80 and the polarizing and reflecting element 70 are stacked to form a second composite film 94, and the second composite film 94 is disposed on the surface of the first lens 10 close to the display 40.

Table 2 shows the optical parameters of each lens in the optical module provided in example 2.

TABLE 2

In the optical module of embodiment 2, the movable lens 20 can be moved in the direction of the optical axis away from the display 40, as shown in fig. 11 for left side movement, to achieve diopter adjustment of 500 degrees of myopia. The movable lens 20 is also movable in the direction of optical axis approaching the display 40, as shown to the right in figure 12, to achieve diopter adjustment for distance vision of 200 degrees.

The optical performance of the optical module provided in embodiment 2 can be as shown in fig. 13 to 16: fig. 13 is a MTF curve graph of an optical module according to embodiment 2 of the present invention, fig. 14 is a schematic view of a dotted line graph of an optical module according to embodiment 2 of the present invention, fig. 15 is a distortion graph of a field curvature according to embodiment 2 of the present invention, and fig. 16 is a vertical axis chromatic aberration diagram according to embodiment 2 of the present invention.

As shown in FIG. 13, MTF in this example 2 is >0.7 at 40lp/mm, and the image is clear.

As shown in fig. 14, in the present embodiment 2, the maximum value of the image points in the dot array image corresponds to the maximum field of view, and the maximum value of the image points in the dot array image is smaller than 13 μm.

As shown in fig. 15, in the present embodiment 2, distortion occurs at the maximum in 1 field of view, and the absolute value is less than 30%.

As shown in fig. 16, in this embodiment 2, the maximum color difference value of the optical module is less than 170 μm.

Example 3

The optical module provided in example 3 is different from the optical module of example 2 in optical parameters, as shown in fig. 17, and table 3 shows the optical parameters of each lens in the optical module provided in example 3.

TABLE 3

In the optical module of embodiment 3, the movable lens 20 can be moved in the direction of the optical axis away from the display 40, as shown in fig. 18 for left side movement, to achieve diopter adjustment of 500 degrees of myopia. The movable lens 20 is also movable in the direction of optical axis approaching the display 40, as shown to the right in figure 19, to achieve diopter adjustment for distance vision of 200 degrees.

As for the optical module provided in embodiment 3, the optical performance of the optical module can be as shown in fig. 20 to 23: fig. 20 is a MTF curve graph of an optical module according to embodiment 3 of the present invention, fig. 21 is a schematic diagram of a dotted line of the optical module according to embodiment 3 of the present invention, fig. 22 is a distortion diagram of a field curvature according to embodiment 3 of the present invention, and fig. 23 is a vertical axis chromatic aberration diagram according to embodiment 3 of the present invention.

As shown in FIG. 20, MTF in this example 3 is >0.4 at 40lp/mm, and the image formation is clear.

As shown in fig. 21, in the present embodiment 3, the maximum value of the image points in the dot sequence image corresponds to the maximum field of view, and the maximum value of the image points in the dot sequence image is smaller than 28 μm.

As shown in fig. 22, in the present embodiment 3, distortion occurs at the maximum in 1 field of view, and the absolute value is less than 30%.

As shown in fig. 23, in this embodiment 3, the maximum color difference value of the optical module is less than 220 μm.

According to the utility model discloses on the other hand, still provide a wear display device, wear display device includes the casing, and as above-mentioned optical module.

Wear display device for example for VR head-mounted apparatus, including VR glasses or VR helmet etc. the embodiment of the utility model provides a do not do specific restriction to this.

The utility model discloses wear display device's concrete implementation can refer to each embodiment of above-mentioned optical module, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, and the repeated description is no longer given here.

In the above embodiments, the differences between the embodiments are described in emphasis, and different optimization features between the embodiments can be combined to form a better embodiment as long as the differences are not contradictory, and further description is omitted here in consideration of brevity of the text.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for purposes of illustration and is not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (11)

1. An optical module, characterized in that it comprises, along the same optical axis, a first lens (10), a movable lens (20) and a display (40); wherein the movable lens (20) is configured to be movable along the optical axis to approach or move away from the display (40);

the optical module further comprises a light splitting element (50), a first phase retarder (60) and a polarization reflection element (70), wherein the first phase retarder (60) is positioned between the light splitting element (50) and the polarization reflection element (70); the light splitting element (50) is arranged on the surface of the movable lens (20) close to the display (40), and the first phase retarder (60) and the polarization reflection element (70) are arranged on either side of the first lens (10);

the optical module further comprises a lens group, the lens group is located between the light splitting element (50) and the display (40), the lens group at least comprises one second lens (30), the minimum distance between the movable lens (20) and the display (40) is L, and L is larger than or equal to 2mm.

2. The optical module according to claim 1, wherein the movable lens (20) is a diopter adjusting optic, the movable lens (20) translating along the optical axis in a range of 0-5 mm.

3. The optical module of claim 1 wherein the optical module is configured to receive a light beam from a light sourceWhen the movable lens (20) moves to the extreme position far away from the display (40), the distance between the surface of the movable lens (20) far away from the display (40) and the surface of the first lens (10) close to the display (40) is L ₁ ，L ₁ ＞0.2mm。

4. Optical module according to claim 1, characterised in that the surface of the movable lens (20) close to the display (40) and the surface of the second lens (30) far from the display (40) are at a distance L when the movable lens (20) is moved to an extreme position close to the display (40) ₂ ，L ₂ ＞0.2mm。

5. The optical module of claim 1, wherein the display (40) is less than 2 inches in size.

6. Optical module according to claim 1, in which the second lens (30) has a central thickness T ₂ ，1mm＜T ₂ < 6mm, the second lens (30) having an optical power of

7. Optical module according to claim 1, in which the movable lens (20) has a central thickness T ₀ ，3mm＜T ₀ < 8mm, the movable lens (20) having an optical power of

8. The optical module according to claim 1, further comprising a polarizer (80), wherein the polarizer (80), the polarizing reflector (70) and the first retarder (60) are sequentially stacked to form a first composite film (93), and the first composite film (93) is disposed on a surface of the first lens (10) close to the display (40).

9. An optical module according to claim 1, characterized in that the first phase retarder (60) is provided on a surface of the movable lens (20) remote from the display (40);

the optical module further comprises a light polarizing element (80), the light polarizing element (80) and the polarization reflecting element (70) are stacked to form a second composite film layer (94), and the second composite film layer (94) is arranged on the surface, close to the display (40), of the first lens (10).

10. The optical module according to claim 1, wherein the display (40) is configured to emit circularly polarized light or linearly polarized light;

when the light emitted by the display (40) is linearly polarized light, a second phase retarder is arranged on the light emitting side of the display (40) and is used for converting the linearly polarized light into circularly polarized light.

11. A head-mounted display device, comprising:

a housing; and

the optical module of any one of claims 1-10.

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