Summary of the invention
In view of the above problems, the invention provides a kind of eyepiece system and head-mounted display, to solve the problem or to solve the problem at least in part.
According to one aspect of the present invention, provide a kind of eyepiece system, this eyepiece system comprises: display screen, concave mirror and positive lens groups;
Described concave mirror, the light for being sent by described display screen reflexes in described positive lens groups;
Described positive lens groups, for the anaclasis of being reflected by described concave mirror in human eye.
Alternatively, described positive lens groups is Fresnel Lenses.
Alternatively, the reflecting surface of described concave mirror is concave spherical surface;
The substrate of described Fresnel Lenses is plane, and its light entrance face is convex aspheric surface, and light-emitting face is the annular Fresnel surface with positive light coke.
Alternatively, the aspheric surface quadratic coefficients of the convex aspheric surface of described Fresnel Lenses is: K2 and K4, meets following relation:
K2<-1,K4<-50。
Alternatively, the focal length of described eyepiece system is f, and the focal length of described concave mirror is f1, and the focal length of described Fresnel Lenses is f2, meets following relation:
3<f1/f<10;
0.3<f2/f<1.2。
Alternatively, described concave mirror and the distance of described display screen on optical axis are L, 20<L<40.
Alternatively, the pitch angle of described concave mirror on the optical axis of described Fresnel Lenses is λ, 30 ° of < λ <60 °.
Alternatively, described Fresnel Lenses adopts plastic material, its refractive index and Abbe number scope respectively: 1.45<n<1.70,50<v<75.
According to another aspect of the present invention, provide a kind of head-mounted display, this head-mounted display comprises the eyepiece system as above described in any one.
Alternatively, described head-mounted display regulates the focal length of described eyepiece system within the specific limits; Described eyepiece system realizes focus adjustment according to the operation of the lens combination that user moves in eyepiece system.
From the above, eyepiece system provided by the invention have employed concave mirror in light transmission process and lens combination cooperatively interacts, decrease the volume of eyepiece system, the light that display screen is produced is assembled and is incided in human eye, forms the virtual image that is upright, that amplify in the front a distance of human eye.Wherein, in the process assembled light, concave mirror assume responsibility for a part of focal power of eyepiece system, alleviates the focal power requirement of eyepiece system to lens combination, not only reduce the aberration that lens combination produces, also the corresponding processing materials decreased lens combination; Again because concave mirror can not produce aberration in the process of converging ray, and then the aberration of eyepiece system can be greatly reduced, improve image quality, reduce quality and the volume of eyepiece system.This eyepiece system is applied to head-mounted display, to the more perfect visual experience of user.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.
Fig. 1 shows a kind of according to an embodiment of the invention schematic diagram of eyepiece system.As shown in Figure 1, this eyepiece system comprises: display screen 110, concave mirror 120, positive lens groups 130 and diaphragm 140.The light that display screen 110 sends reflexes in positive lens groups 130 by concave mirror 120; The anaclasis that concave mirror 120 reflects by positive lens groups 130 is in diaphragm 140; Eyes due to user are positioned at diaphragm 140 place, and the light that display screen 110 sends by the eyepiece system therefore shown in Fig. 1 finally incides in human eye, and before human eye, form a virtual image of amplifying at a distance, human eye finding is this virtual image.
Visible, eyepiece system shown in Fig. 1 have employed concave mirror in light transmission process and lens combination cooperatively interacts, reduce the volume of eyepiece system, the light that display screen is produced is assembled and is incided in human eye, forms the virtual image that is upright, that amplify in the front a distance of human eye.Wherein, in the process assembled light, concave mirror assume responsibility for a part of focal power of eyepiece system, alleviates the focal power requirement of eyepiece system to lens combination, not only reduce the aberration that lens combination produces, can also the processing materials of corresponding minimizing lens combination; Again because concave mirror can not produce aberration in the process of converging ray, and then the aberration of eyepiece system can be greatly reduced, improve image quality, reduce quality and the volume of eyepiece system, to the more perfect visual experience of user.
In one embodiment of the invention, the reflecting surface of the concave mirror 120 in the eyepiece system shown in Fig. 1 is concave spherical surface; Positive lens groups 130 is Fresnel Lenses.In the present embodiment, the whole focal length of the eyepiece system shown in Fig. 1 is f, and the focal length of concave mirror 120 is f1, and the focal length of Fresnel Lenses 130 is f2, meets following relation: 3<f1/f<10; 0.3<f2/f<1.2.Concave mirror 120 and the distance of display screen 110 on optical axis are L, 20<L<40.Further, the pitch angle of concave mirror 120 on the optical axis of Fresnel Lenses 130 is λ, 30 ° of < λ <60 °.
Fig. 2 A shows the schematic diagram of Fresnel Lenses according to an embodiment of the invention, as shown in Figure 2 A, the light entrance face 131 of this Fresnel Lenses 130 is convex aspheric surface, simultaneously its effect makes convergence of rays allow the outer chief ray of axle bend towards optical axis, in the present embodiment, the aspheric surface quadratic coefficients of this light entrance face 131 is: K2 and K4, meets following relation: K2<-1, K4<-50; Light-emitting face 132 is for having the annular Fresnel surface of positive light coke.Fig. 2 B show according to an embodiment of the invention with the schematic diagram of the ordinary lens of Fresnel Lenses equivalence.As shown in Figure 2 B, the light entrance face 151 of this ordinary lens 150 is and the identical convex aspheric surface of light entrance face 131 shown in Fig. 2 A, and light-emitting face 152 is convex surfaces completely equivalent with the light-emitting face 132 shown in Fig. 2 A.The Fresnel Lenses of the complete equivalence shown in comparison diagram 2A and Fig. 2 B and ordinary lens, can see, compare ordinary lens, Fresnel Lenses is by marking off as multiple concentric circles lines (i.e. Fresnel-zone countless in series of theories by lens, as shown in the light-emitting face 132 in Fig. 2 A) reach identical optical effect, save the consumption of material simultaneously, effectively alleviate quality and the volume of eyepiece system.In one embodiment of the invention, the Fresnel Lenses shown in Fig. 2 A is processing and fabricating on a planar base, reduces difficulty of processing, improves working (machining) efficiency.
In one embodiment of the invention, Fresnel Lenses 130 shown in Fig. 2 A adopts plastic material, its refractive index and Abbe number scope be respectively: 1.45<n<1.70,50<v<75; Particularly, adopt the plastic material of E48R model, its refractive index and Abbe number are respectively: n=1.531160, v=56.04.By adopting plastic material processing and manufacturing Fresnel Lenses, reducing difficulty of processing and processing cost further, reducing the quality of eyepiece system simultaneously.
Based on each feature mentioned above, the eyepiece system shown in Fig. 1 achieves the field angle of 50 °, adapts to the display screen of 5.5 cun, and light is sent by display screen and form a virtual image of amplifying at a distance first 5 meters of human eye after eyepiece system imaging.
Fig. 3 shows the point range figure of eyepiece system according to an embodiment of the invention, and point range figure ignores diffraction effect, reflection be the geometry of optical system imaging.In the point range figure of large aberration system, the distribution of point can the energy distribution of representative point picture approx.Therefore, in image quality evaluation, the dense degree of available point range figure more intuitively reflects and weighs the quality of system imaging quality.The aberration of eyepiece system is not clearly as can be seen from Figure 3, and other aberrations have also been obtained good correction, can meet user and use eyepiece system to watch the demand of shown image on display screen.
Present invention also offers a kind of head-mounted display, this head-mounted display comprises the eyepiece system as above described in any one embodiment.In one embodiment, head-mounted display can regulate the focal length of eyepiece system within the specific limits, makes the eyepiece system in head-mounted display be applicable to myopia population; Particularly, head-mounted display is the pattern that user provides the lens combination that can move in eyepiece system, user can according to self-demand, the position of active adjustment lens combination on optical axis, eyepiece system realizes focus adjustment according to the operation of the lens combination that user moves in eyepiece system, makes its focal length adapt to the human eye perception of myopia population.Based on the parameters of above described eyepiece system, the eyepiece system of head-mounted display provided by the invention can be applicable to the crowd of myopia less than 500 degree.
From the above, eyepiece system provided by the invention have employed concave mirror in light transmission process and lens combination cooperatively interacts, and the light that display screen is produced is assembled and incided in human eye, forms the virtual image that is upright, that amplify in the front a distance of human eye.Have following beneficial effect: 1, in the process assembled light, concave mirror assume responsibility for a part of focal power of eyepiece system, alleviates the focal power requirement of eyepiece system to lens combination, namely decreases the aberration that lens combination produces; Again because concave mirror can not produce aberration in the process of converging ray, and then the aberration of eyepiece system can be greatly reduced, improve image quality.2, by adopting Fresnel Lenses as lens combination, greatly lens material be can save, quality and the volume of eyepiece system reduced.3, Fresnel Lenses adopts planar substrates to process, and adopts plastic material, reduces difficulty of processing and the processing cost of eyepiece system, improves working (machining) efficiency.
This eyepiece system is applied to head-mounted display, reduce quality and the volume of head-mounted display, improve the image quality of head-mounted display, reduce difficulty of processing and the processing cost of head-mounted display, still further provides and regulate the function of the focal length of eyepiece system to make head-mounted display adapt to myopia population.Technical scheme provided by the invention drastically increases experience effect and the comfortableness that user uses head-mounted display, to the more perfect visual experience of user.
The foregoing is only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.All any amendments done within the spirit and principles in the present invention, equivalent replacement, improvement etc., be all included in protection scope of the present invention.